As
filed with the Securities and Exchange Commission on June
2, 2009





Registration
No. 333-______





SECURITIES
AND EXCHANGE COMMISSION


Washington,
D.C. 20549




FORM
S-3


REGISTRATION
STATEMENT


Under


The
Securities Act of 1933




PLX
TECHNOLOGY, INC.


(Exact
name of Registrant as specified in its charter)




Delaware
            
            870
      W. Maude Avenue
            
            94-3008334(State
      or other jurisdiction of
              incorporation
      or organization)
            
            Sunnyvale,
      California 94085
              (408)
      774-9060
            
            (I.R.S.
      Employer
              Identification
      Number)





(Address,
including zip code, and telephone number, including area code, of Registrant’s
principal executive offices)




Arthur
Whipple


Chief
Financial Officer


PLX
Technology, Inc.


870
W. Maude Avenue


Sunnyvale,
California 94085


(408)
774-9060





(Name,
address, including zip code, and telephone number, including area code, of agent
for service)




Copies
to:


Stephen
J. Schrader, Esq.


Baker
& McKenzie LLP


Two
Embarcadero Center, 11th
Floor


San
Francisco, California 94111


(415)
576-3000







Approximate date of commencement of
proposed sale to the public:    As soon as
practicable after the effective date of this Registration
Statement.





If the
only securities being registered on this Form are being offered pursuant to
dividend or interest reinvestment plans, please check the following
box.   ̈





If any of
the securities being registered on this Form are to be offered on a delayed or
continuous basis pursuant to Rule 415 under the Securities Act of 1933, other
than securities offered only in connection with dividend or interest
reinvestment plans, check the following box.  x





If this
Form is filed to register additional securities for an offering pursuant to Rule
462(b) under the Securities Act, please check the following box and list the
Securities Act registration statement number of the earlier effective
registration statement for the same offering.   ̈





If this
Form is a post-effective amendment filed pursuant to Rule 462(c) under the
Securities Act, check the following box and list the Securities Act registration
statement number of the earlier effective registration statement for the same
offering.   ̈





If this
Form is a registration statement pursuant to General Instruction I.D. or a
post-effective amendment thereto that shall become effective upon filing with
the Commission pursuant to Rule 462(e) under the Securities Act, check the
following box.   ̈









If this
Form is a post-effective amendment to a registration statement filed pursuant to
General Instruction I.D. filed to register additional securities or additional
classes of securities pursuant to Rule 413(b) under the Securities Act, check
the following box.   ̈





Indicate
by check mark whether the registrant is a large accelerated filer, an
accelerated filer, a non-accelerated filer, or a smaller reporting
company.  See the definitions of “large accelerated filer”,
“accelerated filer” and “smaller reporting company” in Rule 12b-2 of the
Exchange Act.





Large
accelerated filer   ̈Accelerated
filer  x Non-accelerated
filer   ̈(Do not check if a smaller reporting company)Smaller reporting company   ̈







CALCULATION
OF REGISTRATION FEE







Title
      of Each Class of Securities to be Registered
              Amount
      to be Registered
              Proposed
      Maximum Offering Price Per Share(1)
              Proposed
      Maximum Aggregate Offering Price(1)
              Amount
      ofRegistration
      Fee(2)Common
      Stock(1) $0.001 par value
              3,400,000
      shares
              $2.90
              $9,860,000
              $550.19




(1)
            Estimated
      solely for the purpose of computing the amount of the registration fee.
      The estimated fee is made pursuant to Rule 457(c) of the Securities Act of
      1933, as amended, based on the $2.90 average of the high and low sales
      prices as reported by The NASDAQ Stock Market LLC on May 22,
      2009.





The
Registrant hereby amends this Registration Statement on such date or dates as
may be necessary to delay its effective date until the Registrant shall file a
further amendment which specifically states that this Registration Statement
shall thereafter become effective in accordance with Section 8(a) of the
Securities Act of 1933 or until the Registration Statement shall become
effective on such date as the Commission acting pursuant to said Section 8(a)
may determine.




2




The
information in this prospectus is not complete and may be changed. We may not
sell these securities until the registration statement filed with the Securities
and Exchange Commission is effective. This prospectus is not an offer to sell
these securities and we are not soliciting an offer to buy these securities in
any state where the offer or sale is not permitted.





SUBJECT
TO COMPLETION DATED JUNE 2, 2009





PLX
TECHNOLOGY, INC.











3,400,000
SHARES


COMMON
STOCK





This
prospectus relates to up to 3,400,000 shares of our common stock, all of which
may be offered and sold from time to time by certain stockholders of PLX
Technology, Inc. See “Selling Stockholders.” These shares were issued to the
selling stockholders in satisfaction of a promissory note in the principal
amount of $14,200,000 issued in connection with our acquisition in January 2009
of all of the outstanding capital stock of Oxford Semiconductor, Inc. (the
“Acquisition”).  Our common stock issued to the selling stockholders
in the Acquisition was issued pursuant to an exemption from the registration
requirements of the Securities Act of 1933, as amended, provided by Section 4(2)
thereof.





The
selling stockholders will receive all of the net proceeds from the sale of the
shares under this prospectus and will pay all brokerage fees and selling
commissions, if any, applicable to the sale of the shares. We will not receive
any proceeds from the sale of shares by the selling stockholders.





Our
common stock is listed on The NASDAQ Stock Market LLC under the symbol “PLXT.”
On May 22, 2009, the closing sales price of our common stock as reported by The
NASDAQ Stock Market LLC was $2.95 per share.





You
should consider carefully the risk factors
beginning on page 5 of this prospectus before purchasing any of our common stock
offered under this prospectus.




Neither
the Securities and Exchange Commission nor any state securities commission has
approved or disapproved of these securities, or determined if this prospectus is
truthful or complete. Any representation to the contrary is a criminal
offense.




The date
of this prospectus
is             ,
2009




3




TABLE
OF CONTENTS


PageForward-Looking
      Information
              4Risk
      Factors
              5Use
      of Proceeds
              13PLX
      Technology, Inc.
              13Selling
      Stockholders
              13Plan
      of Distribution
              16Description
      Of Capital Stock
              16Legal
      Matters
              18Experts
              18Where
      to Find Additional Information About PLX Technology
              18Information
      Incorporated By Reference
              19


You
should rely only on the information contained in this prospectus. We have not
authorized anyone to provide you with information different from that contained
in this prospectus. The selling stockholders are offering to sell, and seeking
offers to buy, the shares only in jurisdictions where offers and sales are
permitted. The information contained in this prospectus is accurate only as of
the date of this prospectus, regardless of the time of delivery of this
prospectus or of any sale of the shares.





FORWARD-LOOKING INFORMATION




The
statements contained in prospectus that are not purely historical are
forward-looking statements within the meaning of Section 27A of the Securities
Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934,
as amended, including, without limitation, statements regarding our
expectations, objectives, anticipations, plans, hopes, beliefs, intentions or
strategies regarding the future. Forward-looking statements include, without
limitation, the statements regarding:





·
            our
      expectation that there will continue to be a significant fluctuation in
      our quarterly operating results,


·
              our
      belief that sales of our products to a relatively small number of
      customers will continue to account for a significant portion of our net
      sales,
 ·
              our
      expectation that we will continue to invest in future research and
      development,


·
            our
      belief that our growth prospects depend upon our ability to gain customer
      acceptance,


·
            our
      expectation that we will continue to expend a significant amount of time
      and resources for product development and
  refinement,


·
            our
      belief that we must maintain and cultivate relationships with electronic
      equipment manufacturers to obtain broad penetration in the markets for our
      products, and


·
            our
      belief that our products have a competitive advantage due to the
      availability of development tools offered by third
  parties.




All
forward-looking statements included in this document are based on information
available to us on the date hereof, and we assume no obligation to update any
such forward-looking statements. It is important to note that our actual results
could differ materially from those included in such forward-looking statements.
These cautionary statements should be considered in the context of the risks
described under the heading "Risk Factors" beginning on page 5 of this
prospectus, or in the documents incorporated by reference in this prospectus.
You are cautioned not to place undue reliance on forward-looking statements
contained in this prospectus.




4




RISK FACTORS





An
investment in the common stock offered by this prospectus involves a number of
risks. Before making an investment decision, you should carefully read the
entire prospectus, including this section and the documents incorporated by
reference into this prospectus. Additional risks and uncertainties that are not
yet identified or that we currently think are immaterial may also materially
harm our business, operating results and financial condition and could result in
a complete loss of your investment.





Global
Economic Conditions May Continue to Have an Adverse Effect on Our Businesses and
Results of Operations.





The
recent severe tightening of the credit markets, turmoil in the financial
markets, and weakening global economy are contributing to slowdowns in the
industries in which we operate.  Economic uncertainty exacerbates
negative trends in spending and may cause certain customers to push out, cancel,
or refrain from placing orders, which may reduce revenue. Difficulties in
obtaining capital and deteriorating market conditions may also lead to the
inability of some customers to obtain affordable financing, resulting in lower
sales. Customers with liquidity issues may lead to additional bad debt expense.
These conditions may also similarly affect key suppliers, which could affect
their ability to deliver parts and result in delays in the availability of
product.  Further, these conditions and uncertainty about future
economic conditions make it challenging for us to forecast our operating
results, make business decisions, and identify the risks that may affect our
business, financial condition and results of operations. In addition, we
maintain an investment portfolio that is subject to general credit, liquidity,
market and interest rate risks that may be exacerbated by deteriorating
financial market conditions and, as a result, the value and liquidity of the
investment portfolio could be negatively impacted and lead to
impairment.  If the current economic conditions are prolonged or
deteriorate further, or if we are not able to timely and appropriately adapt to
changes resulting from the difficult macroeconomic environment, our business,
financial condition or results of operations may be materially and adversely
affected.





Our
Operating Results May Fluctuate Significantly Due To Factors Which Are Not
Within Our Control





Our
quarterly operating results have fluctuated significantly in the past and are
expected to fluctuate significantly in the future based on a number of factors,
many of which are not under our control.  Our operating expenses,
which include product development costs and selling, general and administrative
expenses, are relatively fixed in the short-term.  If our revenues are
lower than we expect because we sell fewer semiconductor devices, delay the
release of new products or the announcement of new features, or for other
reasons, we may not be able to quickly reduce our spending in
response.





Other
circumstances that can affect our operating results include:




·
            the
      timing of significant orders, order cancellations and
      reschedulings;


·
            the
      loss of one or more significant
customers;


·
            introduction
      of products and technologies by our
competitors;


·
            the
      availability of production capacity at the fabrication facilities that
      manufacture our products;


·
            our
      significant customers could lose market share that may affect our
      business;


·
            integration
      of our product functionality into our customers’
  products;


·
            our
      ability to develop, introduce and market new products and technologies on
      a timely basis;


·
            unexpected
      issues that may arise with devices in
  production;


·
            shifts
      in our product mix toward lower margin
products;


·
            changes
      in our pricing policies or those of our competitors or suppliers,
      including decreases in unit average selling prices of our
      products;


·
            the
      availability and cost of materials to our
  suppliers;


·
            general
      macro economic conditions; and


·
            political
      climate.





These
factors are difficult to forecast, and these or other factors could adversely
affect our business.  Any shortfall in our revenues would have a
direct impact on our business.  In addition, fluctuations in our
quarterly results could adversely affect the market price of our common stock in
a manner unrelated to our long-term operating performance.




5




The
Cyclical Nature Of The Semiconductor Industry May Lead To Significant Variances
In The Demand For Our Products





In the
past, the semiconductor industry has been characterized by significant downturns
and wide fluctuations in supply and demand.  Also, during this time,
the industry has experienced significant fluctuations in anticipation of changes
in general economic conditions.  This cyclicality has led to
significant variances in product demand and production capacity.  It
has also accelerated erosion of average selling prices per unit on some of our
products.  We may experience periodic fluctuations in our future
financial results because of industry-wide conditions.





Because
A Substantial Portion Of Our Net Sales Is Generated By A Small Number Of Large
Customers, If Any Of These Customers Delays Or Reduces Its Orders, Our Net
Revenues And Earnings Will Be Harmed





Historically,
a relatively small number of customers have accounted for a significant portion
of our net revenues in any particular period.  For the three months ended March 31,
2009, Excelpoint Systems Pte Ltd and Promate Electronics Co., Ltd accounted for
21% and 14%, respectively, of net revenues. For the same period in 2008,Excelpoint Systems Pte Ltd
Answer Technology, Inc. and Avnet, Inc. accounted for 30%, 12% and 12%,
respectively, of net revenues.For both periods, no other individual
direct customer or distributor represented greater than 10% of net
revenues.





We have
no long-term volume purchase commitments from any of our significant customers.
We cannot be certain that our current customers will continue to place orders
with us, that orders by existing customers will continue at the levels of
previous periods or that we will be able to obtain orders from new customers. In
addition, some of our customers supply products to end-market purchasers and any
of these end-market purchasers could choose to reduce or eliminate orders for
our customers' products. This would in turn lower our customers' orders for our
products.





We
anticipate that sales of our products to a relatively small number of customers
will continue to account for a significant portion of our net
sales.  Due to these factors, the following have in the past and may
in the future reduce our net sales or earnings:




·
            the
      reduction, delay or cancellation of orders from one or more of our
      significant customers;


·
            the
      selection of competing products or in-house design by one or more of our
      current customers;


·
            the
      loss of one or more of our current customers;
or


·
            a
      failure of one or more of our current customers to pay our
      invoices.





Intense
Competition In The Markets In Which We Operate May Reduce The Demand For Or
Prices Of Our Products





Competition
in the semiconductor industry is intense.  If our main target market,
the microprocessor-based systems market, continues to grow, the number of
competitors may increase significantly.  In addition, new
semiconductor technology may lead to new products that can perform similar
functions as our products.  Some of our competitors and other
semiconductor companies may develop and introduce products that integrate into a
single semiconductor device the functions performed by our semiconductor
devices.  This would eliminate the need for our products in some
applications.





In
addition, competition in our markets comes from companies of various sizes, many
of which are significantly larger and have greater financial and other resources
than we do and thus can better withstand adverse economic or market conditions.
Therefore, we cannot assure you that we will be able to compete successfully in
the future against existing or new competitors, and increased competition may
adversely affect our business.  See “Business -- Products,” and “--
Competition” in Part I of Item I of our Form 10-K for the year ended December
31, 2008.





6


Our
Independent Manufacturers May Not Be Able To Meet Our Manufacturing
Requirements





We do not
manufacture any of our semiconductor devices.  Therefore, we are
referred to in the semiconductor industry as a “fabless” producer of
semiconductors. Consequently, we depend upon third party manufacturers to
produce semiconductors that meet our specifications.  We currently
have third party manufacturers located in China, Japan, Korea, Malaysia,
Singapore and Taiwan, that can produce semiconductors which meet our
needs.  However, as the semiconductor industry continues to progress
towards smaller manufacturing and design geometries, the complexities of
producing semiconductors will increase.  Decreasing geometries may
introduce new problems and delays that may affect product development and
deliveries.  Due to the nature of the semiconductor industry and our
status as a fabless semiconductor company, we could encounter
fabrication-related problems that may affect the availability of our
semiconductor devices, delay our shipments or may increase our
costs.





Only a small number of our
semiconductor devices are currently manufactured by more than one
supplier.We place our orders on a purchase order basis and do
not have a long term purchase agreement with any of our existing
suppliers.  In the event that the supplier of a semiconductor device
was unable or unwilling to continue to manufacture our products in the required
volume, we would have to identify and qualify a substitute
supplier.  Introducing new products or transferring existing products
to a new third party manufacturer or process may result in unforeseen device
specification and operating problems.  These problems may affect
product shipments and may be costly to correct.  Silicon fabrication
capacity may also change, or the costs per silicon wafer may
increase.  Manufacturing-related problems may have a material adverse
effect on our business.





Lower
Demand For Our Customers’ Products Will Result In Lower Demand For Our
Products





Demand
for our products depends in large part on the development and expansion of the
high-performance microprocessor-based systems markets including networking and
telecommunications, enterprise and customer storage, imaging and industrial
applications.  The size and rate of growth of these
microprocessor-based systems markets may in the future fluctuate significantly
based on numerous factors.  These factors include the adoption of
alternative technologies, capital spending levels and general economic
conditions. Demand for products that incorporate high-performance
microprocessor-based systems may not grow.





Our
Lengthy Sales Cycle Can Result In Uncertainty And Delays With Regard To Our
Expected Revenues





Our
customers typically perform numerous tests and extensively evaluate our products
before incorporating them into their systems.  The time required for
test, evaluation and design of our products into a customer’s equipment can
range from six to twelve months or more.  It can take an additional
six to twelve months or more before a customer commences volume shipments of
equipment that incorporates our products.  Because of this lengthy
sales cycle, we may experience a delay between the time when we increase
expenses for research and development and sales and marketing efforts and the
time when we generate higher revenues, if any, from these
expenditures.





In
addition, the delays inherent in our lengthy sales cycle raise additional risks
of customer decisions to cancel or change product plans.  When we
achieve a design win, there can be no assurance that the customer will
ultimately ship products incorporating our products.  Our business
could be materially adversely affected if a significant customer curtails,
reduces or delays orders during our sales cycle or chooses not to release
products incorporating our products.





7


Failure
To Have Our Products Designed Into The Products Of Electronic Equipment
Manufacturers Will Result In Reduced Sales





Our
future success depends on electronic equipment manufacturers that design our
semiconductor devices into their systems.  We must anticipate market
trends and the price, performance and functionality requirements of current and
potential future electronic equipment manufacturers and must successfully
develop and manufacture products that meet these requirements.  In
addition, we must meet the timing requirements of these electronic equipment
manufacturers and must make products available to them in sufficient
quantities.  These electronic equipment manufacturers could develop
products that provide the same or similar functionality as one or more of our
products and render these products obsolete in their applications.





We do not
have purchase agreements with our customers that contain minimum
purchase  requirements.  Instead, electronic equipment
manufacturers purchase our products pursuant to short-term purchase orders that
may be canceled without charge. We believe that in order to obtain broad
penetration in the markets for our products, we must maintain and cultivate
relationships, directly or through our distributors, with electronic equipment
manufacturers that are leaders in the embedded systems
markets.  Accordingly, we will incur significant expenditures in order
to build relationships with electronic equipment manufacturers prior to volume
sales of new products. If we fail to develop relationships with additional
electronic equipment manufacturers to have our products designed into new
microprocessor-based systems or to develop sufficient new products to replace
products that have become obsolete, our business would be materially adversely
affected.





Defects
In Our Products Could Increase Our Costs And Delay Our Product
Shipments





Our
products are complex. While we test our products, these products may still have
errors, defects or bugs that we find only after commercial production has begun.
We have experienced errors, defects and bugs in the past in connection with new
products.





Our
customers may not purchase our products if the products have reliability,
quality or compatibility problems. This delay in acceptance could make it more
difficult to retain our existing customers and to attract new
customers.  Moreover, product errors, defects or bugs could result in
additional development costs, diversion of technical and other resources from
our other development efforts, claims by our customers or others against us, or
the loss of credibility with our current and prospective customers. In the past,
the additional time required to correct defects has caused delays in product
shipments and resulted in lower revenues. We may have to spend significant
amounts of capital and resources to address and fix problems in new
products.





We must
continuously develop our products using new process technology with smaller
geometries to remain competitive on a cost and performance
basis.  Migrating to new technologies is a challenging task requiring
new design skills, methods and tools and is difficult to achieve.





Failure
Of Our Products To Gain Market Acceptance Would Adversely Affect Our Financial
Condition





We
believe that our growth prospects depend upon our ability to gain customer
acceptance of our products and technology.  Market acceptance of
products depends upon numerous factors, including compatibility with other
products, adoption of relevant interconnect standards, perceived advantages over
competing products and the level of customer service available to support such
products.  There can be no assurance that growth in sales of new
products will continue or that we will be successful in obtaining broad market
acceptance of our products and technology.





We expect
to spend a significant amount of time and resources to develop new products and
refine existing products. In light of the long product development cycles
inherent in our industry, these expenditures will be made well in advance of the
prospect of deriving revenues from the sale of any new products. Our ability to
commercially introduce and successfully market any new products is subject to a
wide variety of challenges during this development cycle, including start-up
bugs, design defects and other matters that could delay introduction of these
products to the marketplace. In addition, since our customers are not obligated
by long-term contracts to purchase our products, our anticipated product orders
may not materialize, or orders that do materialize may be cancelled. As a
result, if we do not achieve market acceptance of new products, we may not be
able to realize sufficient sales of our products in order to recoup research and
development expenditures. The failure of any of our new products to achieve
market acceptance would harm our business, financial condition, results of
operation and cash flows.




8




A
Large Portion Of Our Revenues Is Derived From Sales To Third-Party Distributors
Who May Terminate Their Relationships With Us At Any Time





We depend
on distributors to sell a significant portion of our products. For the three
months ended March 31, 2009 and 2008, sales through distributors accounted for
approximately 85% and 78%, respectively, of our net revenues.  Some of
our distributors also market and sell competing
products.  Distributors may terminate their relationships with us at
any time.  Our future performance will depend in part on our ability
to attract additional distributors that will be able to market and support our
products effectively, especially in markets in which we have not previously
distributed our products. We may lose one or more of our current distributors or
may not be able to recruit additional or replacement distributors. The loss of
one or more of our major distributors could have a material adverse effect on
our business, as we may not be successful in servicing our customers directly or
through manufacturers’ representatives.





The
Demand For Our Products Depends Upon Our Ability To Support Evolving Industry
Standards





A
majority of our revenues are derived from sales of products, which rely on the
PCI Express, PCI, PCI-X, SATA, Ethernet, Firewire and USB
standards.  If markets move away from these standards and begin using
new standards, we may not be able to successfully design and manufacture new
products that use these new standards.  There is also the risk that
new products we develop in response to new standards may not be accepted in the
market.  In addition, these standards are continuously evolving, and
we may not be able to modify our products to address new
specifications.  Any of these events would have a material adverse
effect on our business.





We
Must Make Significant Research And Development Expenditures Prior To Generating
Revenues From Products





To
establish market acceptance of a new semiconductor device, we must dedicate
significant resources to research and development, production and sales and
marketing.  We incur substantial costs in developing, manufacturing
and selling a new product, which often significantly precede meaningful revenues
from the sale of this product.  Consequently, new products can require
significant time and investment to achieve profitability.  Investors
should understand that our efforts to introduce new semiconductor devices or
other products or services may not be successful or profitable.  In
addition, products or technologies developed by others may render our products
or technologies obsolete or noncompetitive.





We record
as expenses the costs related to the development of new semiconductor devices
and other products as these expenses are incurred.  As a result, our
profitability from quarter to quarter and from year to year may be adversely
affected by the number and timing of our new product launches in any period and
the level of acceptance gained by these products.





Our
Transition To A New Chief Executive Officer May Not Be Successful





On
November 3, 2008, our board of directors appointed Ralph Schmitt as our chief
executive officer and as a member of our board of directors.  Mike
Salameh, retired as chief executive officer, continued as a full-time employee
for a short transition period and continues to serve as a member of the board of
directors.  While we have planned carefully for this transition, there
are no assurances that we will be able to implement a smooth transition to our
new chief executive officer. Any failure to effectively transition the chief
executive officer position could have a material adverse effect on our business,
results of operations or financial condition.





We
Could Lose Key Personnel Due To Competitive Market Conditions And
Attrition





Our
success depends to a significant extent upon our senior management and key
technical and sales personnel.  The loss of one or more of these
employees could have a material adverse effect on our business.  We do
not have employment contracts with any of our executive officers.





Our
success also depends on our ability to attract and retain qualified technical,
sales and marketing, customer support, financial and accounting, and managerial
personnel.  Competition for such personnel in the semiconductor
industry is intense, and we may not be able to retain our key personnel or to
attract, assimilate or retain other highly qualified personnel in the
future.  In addition, we may lose key personnel due to attrition,
including health, family and other reasons.  We have experienced, and
may continue to experience, difficulty in hiring and retaining candidates with
appropriate qualifications.  If we do not succeed in hiring and
retaining candidates with appropriate qualifications, our business could be
materially adversely affected.




9




The
Successful Marketing And Sales Of Our Products Depend Upon Our Third Party
Relationships, Which Are Not Supported By Written Agreements





When
marketing and selling our semiconductor devices, we believe we enjoy a
competitive advantage based on the availability of development tools offered by
third parties.  These development tools are used principally for the
design of other parts of the microprocessor-based system but also work with our
products.  We will lose this advantage if these third party tool
vendors cease to provide these tools for existing products or do not offer them
for our future products.  This event could have a material adverse
effect on our business.  We have no written agreements with these
third parties, and these parties could choose to stop providing these tools at
any time.





Our
Limited Ability To Protect Our Intellectual Property And Proprietary Rights
Could Adversely Affect Our Competitive Position





Our
future success and competitive position depend upon our ability to obtain and
maintain proprietary technology used in our principal
products.  Currently, we have limited protection of our intellectual
property in the form of patents and rely instead on trade secret
protection.  Our existing or future patents may be invalidated,
circumvented, challenged or licensed to others.  The rights granted
there under may not provide competitive advantages to us.  In
addition, our future patent applications may not be issued with the scope of the
claims sought by us, if at all.  Furthermore, others may develop
technologies that are similar or superior to our technology, duplicate our
technology or design around the patents owned or licensed by us.  In
addition, effective patent, trademark, copyright and trade secret protection may
be unavailable or limited in foreign countries where we may need
protection.  We cannot be sure that steps taken by us to protect our
technology will prevent misappropriation of the technology.





We may
from time to time receive notifications of claims that we may be infringing
patents or other intellectual property rights owned by third
parties.  While there is currently no intellectual property litigation
pending against us, litigation could result in significant expenses to us and
adversely affect sales of the challenged product or technology.  This
litigation could also divert the efforts of our technical and management
personnel, whether or not the litigation is determined in our
favor.  In addition, we may not be able to develop or acquire
non-infringing technology or procure licenses to the infringing technology under
reasonable terms.  This could require expenditures by us of
substantial time and other resources.  Any of these developments would
have a material adverse effect on our business.





If
We Do Not Successfully Integrate Oxford With PLX, We May Not Achieve Our
Anticipated Synergies And Could Adversely Affect Our Financial
Condition




In January
2009, we completed the acquisition of Oxford, a provider of reliable,
high-performance silicon and software solutions to interconnect digital systems,
including serial, parallel, USB, FireWire, Ethernet, SATA and
eSATA.  Although as of
March 31, 2009, we have not encountered significant difficulties with the
integration of Oxford’s operations, there can be no assurance that we will not
encounter substantial difficulties during the completion of the
integration.A substantial delay in the integration of Oxford
could result in a delay or failure to achieve the anticipated synergies, which
could adversely impact our results of operations.  The possible
difficulties of combining the operations of the companies include, but are not
limited to:




·
            the
      integration and consolidation of corporate and administrative
      infrastructures, including computer information
  systems;


·
            the
      integration of the sales force and customer
  base;


·
            possible
      inconsistencies in controls, policies and procedures and business
      cultures;


·
            the
      retention of key employees;


·
            the
      possible diversion of management’s attention from ongoing business
      concerns; and


·
            the
      possibility of costs or inefficiencies associated with the integration of
      the operations of the combined
company.




Our failure
to be successful in addressing these risks or other problems encountered in our
past or future acquisitions could cause us to fail to realize the anticipated
benefits of such acquisitions and could have an adverse impact on our results of
operations.




10


Acquisitions
Could Adversely Affect our Financial Condition and Could Expose Us to
Unanticipated Liabilities




As part of
our business strategy, we expect to continue to review acquisition prospects
that would complement our existing product offerings, improve market coverage or
enhance our technological capabilities.  The Oxford acquisition, as
well as potential future acquisitions, could result in any or all of the
following:




·
            potentially
      dilutive issuances of equity
securities;


·
            large
      acquisition-related write-offs;


·
            potential
      patent and trademark infringement claims against the acquired
      company;


·
            the
      incurrence of debt and contingent liabilities or amortization expenses
      related to other intangible assets;


·
            difficulties
      in the assimilation of operations, personnel, technologies, products and
      the information systems of the acquired
  companies;


·
            the
      incurrence of additional operating losses and expenses of Oxford or other
      potential companies we may acquire;


·
            possible
      delay or failure to achieve expected
synergies;


·
            diversion
      of management’s attention from other business
  concerns;


·
            risks
      of entering geographic and business markets in which we have no or limited
      prior experience; and


·
            potential
      loss of key employees.




In addition,
the registration statement on Form S-3covering 5,600,000 shares of our common
stock, which were issued to Oxford stockholders when the acquisition was
completed, was declared effective by the SEC.  This registration
statement enables the holders of the registered shares to resell those shares in
the public market without legal resale restrictions, if they so choose. We filed
a separate registration statement on Form S-3 on June 2, 2009 to register
for resale the additional 3,400,000 shares that we issued in satisfaction of the
$14.2 million principal balance of the promissory note we issued to Oxford
stockholders on completion of the acquisition.  We cannot predict the
extent, if any, to which the issuance of the additional shares in connection
with the Oxford acquisition would adversely affect the trading price of our
stock, particularly in light of the current financial, stock market and economic
turmoil.




Because
We Sell Our Products To Customers Outside Of The United States And Because Our
Products Are Incorporated With Products Of Others That Are Sold Outside Of The
United States We Face Foreign Business, Political And Economic
Risks





Sales outside
of the United States accounted for approximately 85% of our revenues for the
three months ended March 31, 2009. In 2008 and 2007, sales outside of the United
States accounted for approximately 77% and 71% of our revenues,
respectively.  Sales outside of the United States may fluctuate in
future periods and may continue to account for a large portion of our
revenues.  In addition, equipment manufacturers who incorporate our
products into their products sell their products outside of the United States,
thereby exposing us indirectly to foreign risks.  Further, most of our
semiconductor products are manufactured outside of the United
States.  Accordingly, we are subject to international risks,
including:




·
            difficulties
      in managing distributors;


·
            difficulties
      in staffing and managing foreign subsidiary and branch
      operations;


·
            political
      and economic instability;


·
            foreign
      currency exchange fluctuations;


·
            difficulties
      in accounts receivable collections;


·
            potentially
      adverse tax consequences;


·
            timing
      and availability of export
licenses;


·
            changes
      in regulatory requirements, tariffs and other
  barriers;


·
            difficulties
      in obtaining governmental approvals for telecommunications and other
      products; and


·
            the
      burden of complying with complex foreign laws and
  treaties.





Because
sales of our products have been denominated to date exclusively in United States
dollars, increases in the value of the United States dollar will increase the
price of our products so that they become relatively more expensive to customers
in the local currency of a particular country, which could lead to a reduction
in sales and profitability in that country.




11




We
May Be Required To Record A Significant Charge To Earnings If Our Goodwill,
Amortizable Intangible Assets Or Other Long Lived Asset Become
Impaired


Under
generally accepted accounting principles, we review our amortizable intangible
and long lived assets for impairment when events or changes in circumstances
indicate the carrying value may not be recoverable. Goodwill is tested for
impairment annually, during the fourth quarter and between annual tests in
certain circumstances.  Factors that may be considered a change in
circumstances, indicating that the carrying value of our goodwill, amortizable
intangible assets or other long lived assets may not be recoverable, include a
persistent decline in stock price and market capitalization, reduced future cash
flow estimates, and slower growth rates in our industry. We may be required to
record a significant charge in our financial statements during the period in
which any additional impairment of our goodwill, amortizable intangible assets
or other long lived assets is determined, which would adversely impact our
results of operations.





Our
Principal Stockholders Have Significant Voting Power And May Take Actions That
May Not Be In The Best Interests Of Our Other Stockholders





Our
executive officers, directors and other principal stockholders, in the
aggregate, beneficially own a substantial amount of our outstanding common
stock. Although these stockholders do not have majority control, they currently
have, and likely will continue to have, significant influence with respect to
the election of our directors and approval or disapproval of our significant
corporate actions.  This influence over our affairs might be adverse
to the interests of other stockholders.  In addition, the voting power
of these stockholders could have the effect of delaying or preventing a change
in control of PLX.





The
Anti-Takeover Provisions In Our Certificate of Incorporation Could Adversely
Affect The Rights Of The Holders Of Our Common Stock





Anti-takeover
provisions of Delaware law and our certificate of incorporation may make a
change in control of PLX more difficult, even if a change in control would be
beneficial to the stockholders.  These provisions may allow the board
of directors to prevent changes in the management and control of
PLX.





As part
of our anti-takeover devices, our board of directors has the ability to
determine the terms of preferred stock and issue preferred stock without the
approval of the holders of the common stock.  Our certificate of
incorporation allows the issuance of up to 5,000,000 shares of preferred
stock.  There are no shares of preferred stock
outstanding.  However, because the rights and preferences of any
series of preferred stock may be set by the board of directors in its sole
discretion without approval of the holders of the common stock, the rights and
preferences of this preferred stock may be superior to those of the common
stock.  Accordingly, the rights of the holders of common stock may be
adversely affected.  Consistent with Delaware law, our board of
directors may adopt additional anti-takeover measures in the
future.





12




USE
OF PROCEEDS





We will
not receive any proceeds from the sale of the shares by the selling
stockholders. The selling stockholders will receive all of the net proceeds from
the sale of the shares under this prospectus.








PLX
TECHNOLOGY, INC.





We
develop and supply semiconductor devices that accelerate and manage the transfer
of data in microprocessor-based systems including networking and
telecommunications, enterprise storage, servers, personal computers (PCs), PC
peripherals, consumer electronics, imaging and industrial products. We offer a
complete solution consisting of three related types of products: semiconductor
devices, software development kits and hardware design kits. Our semiconductor
devices manage fast and reliable transfer of data in microprocessor based
systems. Our software development kits and hardware design kits have been
designed with the goal of promoting sales of our semiconductor devices by
lowering customers' development costs and by accelerating their ability to bring
new products to market.





SELLING STOCKHOLDERS





This
prospectus relates to the offer and sale from time to time by the holders of up
to 3,400,000 shares of our common stock issued in satisfaction of the promissory
note in the principal amount of $14,200,000 we issued pursuant to the agreement
and plan of merger between us, Osprey Acquisition Sub, Inc., Oxford
Semiconductor, Inc. and VantagePoint Venture Partners IV (Q), L.P., in its
capacity as stockholder representative, dated as of December 15, 2008, as
amended (the "Merger Agreement").




The following
table provides the names of and the number of shares of our common stock
beneficially owned by each selling stockholder as a result of our acquisition of
Oxford Semiconductor, and the number of shares of such common stock beneficially
owned by each selling stockholder upon completion of the offering or offerings
pursuant to this prospectus, assuming each selling stockholder offers and sells
all of its or his/her respective shares listed below. Selling stockholders may,
however, offer and sell all, or some or none of their shares listed below. Under
some circumstances, the respective donees, pledgees and transferees or other
successors in interest of the selling stockholders may also sell the shares
listed below as being held by the selling stockholders.




Beneficial
ownership is determined in accordance with the rules of the SEC, and includes
voting or investment power with respect to the common stock. Unless otherwise
indicated below, to our knowledge, all persons named in the tables below have
sole voting and investment power with respect to their securities, except to the
extent authority is shared by spouses under applicable law. The inclusion of any
securities in these tables does not constitute an admission of beneficial
ownership by the person named below.




13




The
information in the table below is current as of June 1, 2009, based on a share
ownership report provided by Computershare, Inc., our transfer agent.. The
percentage ownership is based on 37,004,234 shares of common stock outstanding
as of June 1, 2009.




Shares
      Beneficially Owned Prior to Offering
              
              
              
              Shares
      Beneficially Owned After OfferingNumber
ofShares
    BeingSelling
      Stockholder
              
              Number(1)(2)
              
              Percent
              
              Offered(2)
              
              Number
              
              PercentAlcatel
      Venture Fund I, L.P. (3)
              
              
              111,321
              
              
              *
              
              
              42,055
              
              
              0
              
              
              0Patrick
      Arrington
              
              
              363
              
              
              *
              
              
              137
              
              
              0
              
              
              0Michael
      Baghramian
              
              
              2,662
              
              
              *
              
              
              1,006
              
              
              0
              
              
              0Ellen
      Bancroft
              
              
              61
              
              
              *
              
              
              23
              
              
              0
              
              
              0Ed
      Brown
              
              
              10,304
              
              
              *
              
              
              3,893
              
              
              0
              
              
              0Timothy
      Cook
              
              
              37,961
              
              
              *
              
              
              14,341
              
              
              0
              
              
              0Kevin
      D. Debre
              
              
              77
              
              
              *
              
              
              29
              
              
              0
              
              
              0Dirk
      I. Gates Trust (4)
              
              
              7,328
              
              
              *
              
              
              2,769
              
              
              0
              
              
              0Benedict
      Finlay
              
              
              65
              
              
              *
              
              
              25
              
              
              0
              
              
              0Frederick
      C. Goerner Trust
              
              
              1,556
              
              
              *
              
              
              588
              
              
              0
              
              
              0GKM
      SBIC, L.P. (5)
              
              
              85,730
              
              
              *
              
              
              32,387
              
              
              0
              
              
              0Michael
      Holt
              
              
              1,566
              
              
              *
              
              
              592
              
              
              0
              
              
              0Internix,
      Inc. (6)
              
              
              1,566
              
              
              *
              
              
              598
              
              
              0
              
              
              0Isherpa
      Capital Wireless Technology Fund II, L.P. (7)
              
              
              44,876
              
              
              *
              
              
              16,954
              
              
              0
              
              
              0La
      Caisse de Depot et Placement du Quebec (8)
              
              
              3,384,479
              
              
              9.15
              %
              
              1,278,581
              
              
              0
              
              
              0Ian
      M. Laing
              
              
              268,464
              
              
              *
              
              
              101,420
              
              
              0
              
              
              0James
      E. Lewis
              
              
              117,123
              
              
              *
              
              
              44,247
              
              
              0
              
              
              0William
      F. Mackenzie
              
              
              12
              
              
              *
              
              
              5
              
              
              0
              
              
              0Joe
      Meza
              
              
              15
              
              
              *
              
              
              7
              
              
              0
              
              
              0Seyed
      Jalil Oraee-Mirzamani
              
              
              171,656
              
              
              *
              
              
              64,848
              
              
              0
              
              
              0Rolling
      Oaks Capital Fund I, L.P. (9)
              
              
              34,379
              
              
              *
              
              
              12,988
              
              
              0
              
              
              0Shelter
      Venture Fund LP (10)
              
              
              274,922
              
              
              *
              
              
              103,860
              
              
              0
              
              
              0Shelter
      Venture (Parallel)  Fund LP (10)
              
              
              2,741
              
              
              *
              
              
              1,036
              
              
              0
              
              
              0Jay
      Standiford
              
              
              1,556
              
              
              *
              
              
              588
              
              
              0
              
              
              0Strand
      Nominees (12)
              
              
              268,464
              
              
              *
              
              
              101,420
              
              
              0
              
              
              0SV
      Financial Group (fka Silicon Valley Bancshares) (12)
              
              
              511
              
              
              *
              
              
              193
              
              
              0
              
              
              0TCW
      Leveraged Income Trust II L.P. (13)
              
              
              10,545
              
              
              *
              
              
              3,984
              
              
              0
              
              
              0TCW
      Leveraged Income Trust IV L.P. (13)
              
              
              10,545
              
              
              *
              
              
              3,984
              
              
              0
              
              
              0Transdimension
      Investment, L.P. (10)
              
              
              50,272
              
              
              *
              
              
              18,992
              
              
              0
              
              
              0Richard
      Troop
              
              
              788
              
              
              *
              
              
              298
              
              
              0
              
              
              0Sundar
      Vanchinathan
              
              
              9,306
              
              
              *
              
              
              3,516
              
              
              0
              
              
              0VantagePoint
      Venture Partners III (Q), L.P. (14)
              
              
              125,544
              
              
              *
              
              
              47,428
              
              
              0
              
              
              0VantagePoint
      Venture Partners III, L.P. (14)
              
              
              15,281
              
              
              *
              
              
              5,773
              
              
              0
              
              
              0VantagePoint
      Venture Partners IV (Q), L.P. (14)
              
              
              3,576,455
              
              
              9.66
              %
              
              1,351,106
              
              
              0
              
              
              0VantagePoint
      Venture Partners IV Principals Fund, L.P. (14)
              
              
              13,029
              
              
              *
              
              
              4,922
              
              
              0
              
              
              0VantagePoint
      Venture Partners IV, L.P. (14)
              
              
              358,416
              
              
              *
              
              
              135,401
              
              
              0
              
              
              0


*
              Less
      than 1% of the outstanding shares of common
  stock.


(1)
            The
      above table includes shares held in an escrow account to secure
      indemnification obligations, as well as shares held in a separate escrow
      account to reimburse fees incurred by the stockholder representative, in
      each case pursuant to the Merger
Agreement.




(2)
            446,176
      of the shares are held by VantagePoint Venture
      Partners are placed in escrow (the “Trigger Price
      Escrow”) for the benefit of certain former Oxford common
      stockholders. In the event that (i) the average trading price of our
      common stock exceeds $4.75 per share during any 20 consecutive day period
      ending prior to December 15, 2010 or (ii) we are acquired prior to
      December 15, 2010 and the fair market value of the consideration received
      with respect to a share of our common stock exceeds $4.75, these 446,176
      shares will be released to such former Oxford common
      stockholders on a pro rata
basis.




(3)
            The
      voting and investment power over the shares held by Alcatel Venture Fund
      I, L.P. is held by Mr. Steve Kim, its managing
  partner.




(4)
            The
      voting and investment power over the shares held by the Dirk I Gates Trust
      is held by Mr. Dirk Gates.




14




(5)
            The
      voting and investment power over the shares held by GKM SBIC, L.P. is
      shared by Jonathan Bloch and David
Stastny.




(6)
            The
      voting and investment power over the shares held by Internix, Inc. is held
      by Mr. Yoshiharu Fujisawa, its Chairman and Chief Executive
      Officer.




(7)
            The
      voting and investment power over the shares held by Isherpa Capital
      Wireless is held by each of Messrs. Navin Dimond, Peter Nannette, Gary
      Rohr and Vipanj Patel.




(8)
            The
      voting and investment power over the shares held by Rollings Oaks Capital
      Fund I, L.P. is held by each of Messrs. Craig Coleman, Brian Sullivan and
      Michael Rotgin, the general partners of Rollings Oaks Capital,
      LLC.




(9)
            The
      voting and investment power over the shares held by Rollings Oaks Capital
      Fund I, L.P. is held by each of Messrs. Craig Coleman, Brian Sullivan and
      Michael Rotgin, the general partners of Rollings Oaks Capital,
      LLC.




(10)
            The
      voting and investment power over the shares held by Shelter Venture Fund
      LP, Shelter Venture (Parallel) Fund and Transdimension Investment, L.P. is
      held by each of Messrs. Arthur Bilger, Bahram Nour-Omid and Michael
      Rotgin.




(11)
            The
      voting and investment power over the shares held by Strand Nominees is
      held by Mr. Nick Cross.




(12)
            The
      voting and investment power over the shares held by SV Financial Group is
      held by each of Mr. Michael Kruse, Ms. Paulette Mehas and Mr. Michael
      Descheneaux.




(13)
            The
      voting and investment power over the shares held by TCW Leveraged Income
      Trust II L.P. is shared by the officers of TCW Investment Management
      Company, and the shares held by TCW Leveraged Income Trust IV L.P. is
      shared by the officers of TCW Asset Management Company, who are comprised
      of the following individuals: Mr. Steve Kochler, Ms. Melissa Weiler, Mr.
      Michael Parks, Mr. Mark Attanasio, Mr. Jean-Mark Chapus, Mr. James Hasset
      and Mr. Sean Plater.  Any two officers, acting together, may act
      on behalf of the entities.




(14)
            Messrs.
      James Marver and Alan Salzman, as the Managing Members of VantagePoint
      Venture Associates IV, L.L.C. and VantagePoint Venture Associates III,
      L.L.C, the General Partners of the foregoing entities, hold shared voting
      and dispositive power with respect to all of the shares held by the
      VantagePoint entities.  Mr. D. James Guzy, our chairman of the
      board of directors, is the father-in-law of Ms. Melissa
      Guzy.  Ms. Guzy is a member of VantagePoint Venture Associates
      IV, L.L.C., the general partner of VantagePoint Venture Partners IV (Q),
      L.P., VantagePoint Venture Partners IV Principal Funds, L.P. and
      VantagePoint Venture Partners IV, L.P.  Through her membership
      in VantagePoint Venture Associates IV, L.L.C., Ms. Guzy has an indirect
      interest in the shares owned by VantagePoint Venture Partners IV (Q),
      L.P., VantagePoint Venture Partners IV Principals Fund, L.P. and
      VantagePoint Venture Partners IV, L.P. that we believe is not material
      under instructions to applicable SEC rules, and she is not disclosed in
      the Schedule 13G filed by VantagePoint entities as having voting or
      investment power over the shares beneficially owned by VantagePoint
      entities, which are former stockholders of
      Oxford.  .  Mr. Guzy does not own any shares of
      capital stock of, or any other interests in, Oxford Semiconductor or
      VantagePoint Venture Partners.




15


PLAN
OF DISTRIBUTION




The shares of
common stock covered by this prospectus may be offered and sold from time to
time by the selling stockholders listed in this prospectus. We will not receive
any proceeds from this offering. The shares may be sold from time to time to
purchasers directly by any of the selling stockholders, or under some
circumstances, donees, pledgees, transferees or other successors in interest
("Transferees") thereof.




Alternatively, the
selling stockholders, or Transferees thereof, may from time to time offer the
shares through dealers or agents, who may receive compensation in the form of
commissions from the selling stockholders, or Transferees thereof, and/or the
purchasers of the shares for whom they may act as agent. The selling
stockholders or Transferees thereof, and any dealers or agents that participate
in the distribution of the shares may be deemed to be "underwriters" within the
meaning of the Securities Act and any profit on the sale of the shares by them
and any commissions received by any such dealers or agents might be deemed to be
underwriting commissions under the Securities Act.




At a time a
particular offer of the shares is made, a prospectus supplement, if required,
will be distributed that will set forth the name and names of any dealers or
agents and any commissions and other terms constituting compensation from the
selling stockholders, or Transferees thereof, and any other required
information. The shares may be sold from time to time at varying prices
determined at the time of sale or at negotiated prices.




In order to
comply with the securities laws of certain states, if applicable, the shares may
be sold only through registered or licensed brokers or dealers. In addition, in
certain states, the shares may not be sold unless they have been registered or
qualified for sale in such state or an exemption from such registration or
qualification requirement is available and is complied with.




The shares
may also be sold in one or more of the following transactions: (a) block
transactions (which may involve crosses) in which a broker-dealer may sell all
or a portion of such stock as agent but may position and resell all or a portion
of the block as principal to facilitate the transaction; (b) purchases by any
such broker-dealer as principal and resale by such broker-dealer for its own
account pursuant to a prospectus supplement; (c) ordinary brokerage transactions
and transactions in which any such broker-dealer solicits purchasers; (d) sales
"at the market" to or through a market maker or into an existing trading market,
on an exchange or otherwise, for such shares; and (e) sales in other ways not
involving market makers or established trading markets, including direct sales
to purchasers. In effecting sales, broker-dealers engaged by the selling
stockholders may arrange for other broker-dealers to participate.




DESCRIPTION OF CAPITAL STOCK


General





Our
authorized capital stock consists of 50,000,000 shares of common stock, par
value $0.001 per share, and 5,000,000 shares of preferred stock, par value
$0.001 per share. As of June 1, 2009, there were approximately 37,004,234 shares
of PLX common stock outstanding and no shares of preferred stock issued and
outstanding.





Description
of Common Stock





The
holders of our common stock are entitled to one vote per share on all matters to
be voted upon by the stockholders. Stockholders may not cumulate their votes in
the election of directors or with respect to any matter submitted to a vote of
the stockholders. Subject to preferences that may be applicable to any
outstanding preferred stock, the holders of common stock are entitled to receive
ratably such dividends, if any, as may be declared from time to time by our
board of directors out of funds legally available therefore. In the event of
liquidation, dissolution or winding up of PLX, the holders of common stock are
entitled to share ratably in all assets remaining after payment of liabilities,
subject to prior liquidation rights of any outstanding preferred stock. Our
common stock has no preemptive or conversion rights. There are no redemption or
sinking fund provisions applicable to our common stock.




16


Description
of Preferred Stock





Under our
amended and restated certificate of incorporation, our board of directors is
authorized without further stockholder action to provide for the issuance of
5,000,000 shares of our preferred stock, in one or more series, with such voting
powers, full or limited, and with such designations, preferences and relative
participating, optional or other special rights, and qualifications, limitations
or restrictions thereof, as shall be stated in the resolution or resolutions
providing for the issue of a series of such stock adopted, at any time or from
time to time, by our board of directors. The issuance of the preferred stock
could adversely affect the voting power of holders of our common stock and the
likelihood that such holders will receive dividend payments and payments upon
liquidation and could have the effect of delaying, deferring or preventing a
change in control.





Certain
Anti-Takeover, Limited Liability and Indemnification Provisions; Section 203 of
the Delaware General Corporation Law





We are
subject to the provisions of Section 203 of the Delaware General Corporation
Law, an anti-takeover law. In general, the statute prohibits a publicly held
Delaware corporation from engaging in a "business combination" with an
"interested stockholder" for a period of three years after the date of the
transaction in which the person became an interested stockholder, unless the
business combination is approved in a prescribed manner. For purposes of Section
203, a "business combination" includes a merger, asset sale or other transaction
resulting in a financial benefit to the interested stockholder, and an
"interested stockholder" is a person who, together with affiliates and
employees, owns or, within three years prior, did own 15% or more of the
corporation's voting stock.





Stockholder
Action; Special Meetings of Stockholders





Our
amended and restated certificate of incorporation and amended and restated
bylaws require that any action required or permitted to be taken by our
stockholders must be effected at a duly called annual, a special meeting of the
stockholders or may be effected by a consent in writing. In addition, special
meetings of our stockholders may be called only by our chairman of the board of
directors, our president or our board of directors.





Our
Board of Directors





Our
amended and restated certificate of incorporation and amended and restated
bylaws also provide that directors may be removed with or without cause by a
vote of a majority of the stockholders and that vacancies on the board of
directors created either by resignation, death, retirement, disqualification,
removal or by an increase in the size of the board of directors may be filled by
a majority vote of the directors in office. Our amended and restated certificate
of incorporation also specifies that the authorized number of directors may be
changed only by an amendment to our amended and restated certificate of
incorporation or our amended and restated bylaws. These provisions may have the
effect of deterring hostile takeovers or delaying changes in control or
management.





Registration
Rights





In
connection with our acquisition of Oxford Semiconductor in January 2009, we were
required to file with the SEC a registration statement on Form S-3 registering
the shares of our common stock issued to such former Oxford Semiconductor
stockholders. A registration statement on Form S-3 covering 5,600,000 shares of
our common stock (the “Initial Registration Statement”), which were issued to
Oxford stockholders when the Acquisition was completed, has been declared
effective by the SEC.  The former stockholders of Oxford Semiconductor
have been given the opportunity to sell shares of our common stock received by
them in connection with the Acquisition as part of the offering described in
this prospectus as well as the offering described in the Initial
Registration Statement. We are required to maintain the effectiveness of the
registration statement of which this prospectus is part, as well as the Initial
Registration Statement, until the date on which all of the shares offered hereby
and thereby have been sold by the selling stockholders; provided, however, we
will not be required to maintain the effectiveness of either registration
statement at such time that fewer than 900,000 shares offered by both
registration statements in the aggregate have not been sold by the initial
selling stockholders, excluding shares that a selling stockholder may not freely
sell without any restriction or limitation pursuant to Rule 144. We cannot
assure you that we will be able to keep this registration statement continuously
effective for the required period.




17


Transfer
Agent and Registrar





The
transfer agent and registrar for our common stock is Computershare,
Inc.





Listing





Our
common stock is quoted on The NASDAQ Stock Market LLC under the trading symbol
“PLXT.”





LEGAL MATTERS





The
validity of the shares offered under this prospectus has been passed upon for us
by Baker & McKenzie LLP, San Francisco, California.





EXPERTS





The
consolidated financial statements and schedule as of December 31, 2008 and 2007
and for each of the three years in the period ended December 31, 2008 and
management's assessment of the effectiveness of internal control over financial
reporting as of December 31, 2008 incorporated by reference in this Prospectus
have been so incorporated in reliance on the reports of BDO Seidman, LLP, an
independent registered public accounting firm, incorporated herein by reference,
given on the authority of said firm as experts in auditing and
accounting.





The
audited historical financial statements included in exhibit 99.1 of PLX
Technology, Inc.'s Current Report on Form 8-K/A dated March 18, 2009 have been
so incorporated in reliance on the report of PricewaterhouseCoopers LLP,
independent accountants, given on the authority of said firm as experts in
auditing and accounting.




WHERE
TO FIND ADDITIONAL INFORMATION ABOUT PLX TECHNOLOGY





We have
filed reports, proxy statements and other information with the SEC. You may read
and copy any document we file with the SEC at the SEC’s Public Reference Room at
100 F Street, N.W., Washington, D.C. 20549. You may obtain information on
the Public Reference Room by calling the SEC at 1-800-SEC-0330. The SEC
maintains a website that contains the reports, proxy statements and other
information we file electronically with the SEC. The address of the SEC website
is http://www.sec.gov.





We have
filed with the SEC a registration statement, which contains this prospectus, on
Form S-3 under the Securities Act of 1933. The registration statement relates to
the common stock offered by the selling stockholders. This prospectus does not
contain all of the information set forth in the registration statement and the
exhibits and schedules to the registration statement. Please refer to the
registration statement and its exhibits and schedules for further information
with respect to us and our common stock. Statements contained in this prospectus
as to the contents of any contract or other document are not necessarily
complete and, in each instance, we refer you to the copy of that contract or
document filed as an exhibit to the registration statement. You may read and
obtain a copy of the registration statement and its exhibits and schedules from
the SEC.




18


INFORMATION INCORPORATED BY REFERENCE





The SEC
allows us to “incorporate by reference” the information we file with it, which
means that we can disclose important information to you by referring you to
those documents. The information incorporated by reference is considered to be
part of this prospectus, and later information that we file with the SEC will
automatically update and supersede the information contained in this prospectus,
including the information incorporated by reference in this prospectus. We
incorporate by reference the documents listed below, and any future filings we
may make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange
Act prior to the termination of this offering. This prospectus is part of a
registration statement we filed with the SEC. The documents we incorporate by
reference include:





1.
            Our
      Annual Report on Form 10-K for the year ended December 31, 2008 filed with
      the SEC on March 6, 2009.




2.
            Our
      Definitive Proxy Statement on Schedule 14A filed on April 24,
      2009.




3.
            Our
      Quarterly Reports on Form 10-Q for the quarter ended March 31, 2009 filed
      with the SEC on May 8, 2009.




4.
            Our
      Current Reports on Form 8-K filed on January 6, 2009, January 26, 2009,
      March 18, 2009, March 19, 2009, April 14, 2009, May 5, 2009 and May 27,
      2009.




5.
            The
      description of our common stock contained in our registration statement on
      Form 8-A (Reg. No. 000-25699) filed on April 2,
  1999.




6.
            All
      documents subsequently filed by us pursuant to Sections 13(a), 13(c), 14
      or 15(d) of the Exchange Act prior to the termination of this
      offering.





Each of
these filings is available from the SEC as described above.  The
public may read and copy any material we file with the SEC at the SEC’s Public
Reference Room at 100 F Street N.E., Washington, D.C. 20549.  The
public may obtain information on the operation of the Public Reference Room by
calling the SEC at 1-800-SEC-0330.  The SEC maintains an Internet site
that contains reports, proxy and information statements and other information
regarding issuers that file electronically with the SEC at
http://www.sec.gov.





You may
request, and we will provide at no cost, a copy of these filings, including any
exhibits to such filings, by writing or telephoning us at the following address:
Investor Relations, PLX Technology, Inc., 870 W. Maude Avenue, Sunnyvale,
California 94085, telephone number (408) 774-9060.




19


PART
II





INFORMATION
NOT REQUIRED IN PROSPECTUS





ITEM
14.    OTHER EXPENSES OF ISSUANCE AND
DISTRIBUTION





The
following table sets forth the costs and expenses payable by Registrant in
connection with the sale of common stock being registered. All amounts are
estimates except the SEC registration fee.




Amount
      to be PaidSEC
      registration fee
              
              $
              550.19Printing
      expenses
              
              $
              10,000Legal
      fees and expenses
              
              $
              30,000Accounting
      fees and expenses
              
              $
              15,000Miscellaneous
      expenses
              
              $
              5,000Total
              
              $
              60,550.19
  ITEM
15.    INDEMNIFICATION OF DIRECTORS AND
OFFICERS





The
indemnification and liability of the Registrant's directors and officers are
governed by Delaware law.





Under
Section 145 of the General Corporation Law of the State of Delaware, the
Registrant has broad powers to indemnify its directors and officers against
liabilities that they may incur in such capacities, including liabilities under
the Securities Act. The Registrant's bylaws also provide for mandatory
indemnification of its directors and executive officers, and permissive
indemnification of its employees and agents, to the fullest extent permissible
under Delaware law.





The
Registrant's amended and restated certificate of incorporation provides that the
liability of its directors for monetary damages shall be eliminated to the
fullest extent permissible under Delaware law. Pursuant to Delaware law, this
includes elimination of liability for monetary damages for breach of the
directors' fiduciary duty of care to the Registrant and its stockholders. These
provisions do not eliminate the directors' duty of care and, in appropriate
circumstances, equitable remedies such as injunctive or other forms of
non-monetary relief will remain available under Delaware law. In addition, each
director will continue to be subject to liability for breach of the directors'
duty of loyalty to the Registrant for acts or omissions not in good faith or
involving intentional misconduct, for knowing violations of law, for any
transaction from which the director derived an improper personal benefit, and
for payment of dividends or approval of stock repurchases or redemptions that
are unlawful under Delaware law. The provision also does not affect a director's
responsibilities under any other laws, such as the federal securities laws or
state or federal environmental laws.





The
Registrant has obtained a policy of directors' and officers' liability insurance
that insures the Registrant's directors and officers against the cost of
defense, settlement or payment of a judgment under certain
circumstances.




20





ITEM
16.    EXHIBITS





The
following exhibits are filed herewith or incorporated by reference
herein:




Exhibit
      No.
              
              Description2.1
              
              Agreement
      and Plan of Merger, dated as of December 15, 2008 by and among PLX
      Technology, Inc., Osprey Acquisition Sub, Inc., Oxford Semiconductor, Inc.
      and VantagePoint Venture Partners IV (Q), L.P., in its capacity as
      stockholder representative (previously filed as Exhibit 2.1 to the
      Registrant’s Current Report on Form 8-K, filed on December 19, 2008 and
      incorporated herein by reference).2.2
              
              Amendment
      to Agreement and Plan of Merger, dated as of January 2, 2009 by and among
      PLX Technology, Inc., Osprey Acquisition Sub, Inc., Oxford Semiconductor,
      Inc. and VantagePoint Venture Partners IV (Q), L.P., in its capacity as
      stockholder representative (previously filed as Exhibit 2.1 to the
      Registrant’s Current Report on Form 8-K, filed on January 6, 2009 and
      incorporated herein by reference).2.3
              
              Exchange
      Agent Agreement dated January 2, 2009 by and among the Registrant,
      Computershare, Inc. and Computershare Trust Company, N.A. (previously
      filed as Exhibit 2.3 to the Registrant’s Annual Report on Form 10-K for
      the fiscal year ended December 31, 2008, filed on March 6, 2009 and
      incorporated by reference).2.4
              
              Escrow
      Agreement dated January 2, 2009 by and among the Registrant, VantagePoint
      Venture Partners IV (Q), L.P., as representative of the stockholders of
      Oxford Semiconductor, Inc., and Computershare Trust Company, N.A.
      (previously filed as Exhibit 2.4 to the Registrant’s Annual Report on Form
      10-K for the fiscal year ended December 31, 2008, filed on March 6, 2009
      and incorporated by reference).2.5
              
              Form
      of Stockholder Support Agreement dated December 15, 2008 by and among the
      Registrant, Oxford Semiconductor, Inc., VantagePoint Venture Partners IV
      (Q), L.P., as the representative of the stockholders of Oxford
      Semiconductor, Inc., and certain stockholders of the Registrant
      (previously filed as Exhibit 2.5 to the Registrant’s Annual Report on Form
      10-K for the fiscal year ended December 31, 2008, filed on March 6, 2009
      and incorporated by reference).4.1
              
              Amended
      and Restated Certificate of Incorporation of the Registrant (previously
      filed as Exhibit 3.1 to the Registrant's Registration Statement on Form
      S-1 (Registration No. 333-71795) and incorporated herein by
      reference).4.2
              
              Registrant's
      Amended and Restated Bylaws (previously filed as Exhibit 3.1 to the
      Registrant’s Current Report on Form 8-K, filed on November 26, 2007 and
      incorporated herein by reference).4.3
              
              Certificate
      of Amendment to Amended and Restated Certificate of Incorporation
      (previously filed as Exhibit 3.1 to the Registrant’s Quarterly Report on
      Form 10-Q for the quarter ended June 30, 2004 and incorporated herein by
      reference).5.1
              
              Opinion
      of Baker & McKenzie LLP (previously filed as Exhibit 5.1 to the
      Registrant’s Registration Statement on Form S-3 (Registration No.
      333-156760).23.1
              
              Consent
      of Baker & McKenzie LLP (included in Exhibit 5.1).23.2
              
              Consent
      of BDO Seidman, LLP, Independent Registered Public Accounting
      Firm.23.3
              
              Consent
      of PricewaterhouseCoopers, LLP, Independent
Accountants.24.1
              
              Power
      of Attorney (included in the signature page to this Registration
      Statement).


21




ITEM
17.    UNDERTAKINGS





The
Registrant hereby undertakes:





1.    To
file, during any period in which offers or sales are being made, a
post-effective amendment to this registration statement:




(a)
            To
      include any prospectus required by Section 10(a)(3) of the Securities
      Act;




(b)
            To
      reflect in the prospectus any facts or events arising after the effective
      date of this registration statement (or the most recent post-effective
      amendment thereof) which, individually or in the aggregate, represent a
      fundamental change in the information set forth in this registration
      statement.  Notwithstanding the foregoing, any increase or
      decrease in volume of securities offered (if the total dollar value of
      securities offered would not exceed that which was registered) and any
      deviation from the low or high end of the estimated maximum offering range
      may be reflected in the form of prospectus filed with the Commission
      pursuant to Rule 424(b) if, in the aggregate, the changes in volume and
      price represent no more than 20 percent charge in the maximum aggregate
      offering price set forth in the “Calculation of Registration Fee” table in
      the effective registration
statement;




(c)
            To
      include any material information with respect to the plan of distribution
      not previously disclosed in this registration statement or any material
      change to such information in this registration statement or any material
      change to such information in the registration
  statement;




provided, however, that
clauses (a) and (b) do not apply if the information required to be included in a
post-effective amendment by those paragraphs is contained in reports filed with
or furnished to the Commission by the registrant pursuant to section 13 or
section 15(d) of the Securities Exchange Act of 1934 that are incorporated by
reference in the registration statement, or is contained in a form of prospectus
filed pursuant to Rule 424(b) that is part of the registration
statement.




2.    That,
for the purpose of determining any liability under the Securities Act, each such
post-effective amendment shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering
thereof.





3.    To
remove from registration by means of a post-effective amendment any of the
securities being registered which remain unsold at the termination of the
offering.





4.    That,
for the purpose of determining any liability under the Securities Act of 1933,
each filing of the Registrant’s annual report pursuant to Section 13(a) or
Section 15(d) of the Exchange Act, (and, where applicable, each filing of an
employee benefit plan’s annual report pursuant to Section 15(d) of the Exchange
Act) that is incorporated by reference in this registration statement shall be
deemed to be a new registration statement relating to the securities offered
therein, and the offering of such securities at that time shall be deemed to be
the initial bona fide offering thereof.





Insofar
as indemnification for liabilities arising under the Securities Act may be
permitted to directors, officers and controlling persons of the Registrant
pursuant to the foregoing provisions, or otherwise, the Registrant has been
advised that in the opinion of the Securities and Exchange Commission such
indemnification is against public policy as expressed in the Securities Act, and
is, therefore, unenforceable.  In the event that a claim for
indemnification against such liabilities (other than the payment by the
Registrant of expenses incurred or paid by a director, officer or controlling
person of the Registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the Registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities
Act, and will be governed by the final adjudication of such issue.





22


SIGNATURES





Pursuant
to the requirements of the Securities Act of 1933, as amended, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-3 and has duly caused this registration
statement on Form S-3 to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of Sunnyvale, State of California, on this 2nd day
of June, 2009.




PLX TECHNOLOGY,
      INC.By:
              /s/ Ralph
      H. SchmittRalph
      H. SchmittPresident
      and Chief Executive Officer




POWER
OF ATTORNEY





KNOW ALL
BY THESE PRESENTS that each individual whose signature appears below constitutes
and appoints Ralph H. Schmitt and Arthur Whipple, and each of them, as his or
her true and lawful attorneys-in-fact and agent, each with the power of
substitution, for him or her in his or her name, place and stead, in any and all
capacities, to sign the registration statement filed herewith and any and all
amendments (including post-effective amendments) to this registration statement,
and to sign any registration statement for the same offering covered by this
registration statement that is to be effective upon filing pursuant to Rule
462(b) promulgated under the Securities Act, and all post-effective amendments
thereto, and to file the same, with all exhibits thereto and all documents in
connection therewith, with the SEC, granting unto said attorneys-in-fact and
agents, each of them, full power and authority to do and perform each and every
act and thing requisite and necessary to be done in and about the foregoing, as
full to all intents and purposes as he or she might or could do in person,
hereby ratifying and confirming all that said attorneys-in-fact and agents or
any of them, or his, her or their substitute or substitutes, may lawfully do or
cause to be done by virtue hereof.





Pursuant
to the requirements of the Securities Act, this registration statement has been
signed by the following persons in the capacities and on the dates
indicated:




Signature
                
                Title
                
                Date/s/
      Ralph H. Schmitt
                
                President,
      Chief Executive Officer and Director
                
                June
      2, 2009Ralph
      H. Schmitt
                
                (Principal
      Executive Officer)/s/
      Arthur Whipple
                
                Chief
      Financial Officer
                
                June
      2, 2009Arthur
      Whipple
                
                (Principal
      Financial and Accounting Officer)/s/ D. James Guzy
                
                Chairman
      of the Board of Directors
                
                June
      2, 2009D.
      James Guzy/s/ Michael J. Salameh
                
                Director
                
                June
      2, 2009Michael
      J. Salameh/s/
      John H. Hart
                
                Director
                
                June
      2, 2009John
      H. Hart/s/
      Robert H. Smith
                
                Director
                
                June
      2, 2009Robert
      H. Smith/s/
      Thomas Riordan
                
                Director
                
                June
      2, 2009Thomas
      Riordan/s/
      Patrick Verderico
                
                Director
                
                June
      2, 2009Patrick
      Verderico




23


EXHIBIT
INDEX


Exhibit
      No.
                
                Description2.1
                
                Agreement
      and Plan of Merger, dated as of December 15, 2008 by and among PLX
      Technology, Inc., Osprey Acquisition Sub, Inc., Oxford Semiconductor, Inc.
      and VantagePoint Venture Partners IV (Q), L.P., in its capacity as
      stockholder representative (previously filed as Exhibit 2.1 to the
      Registrant’s Current Report on Form 8-K, filed on December 19, 2008 and
      incorporated herein by reference).2.2
                
                Amendment
      to Agreement and Plan of Merger, dated as of January 2, 2009 by and among
      PLX Technology, Inc., Osprey Acquisition Sub, Inc., Oxford Semiconductor,
      Inc. and VantagePoint Venture Partners IV (Q), L.P., in its capacity as
      stockholder representative (previously filed as Exhibit 2.1 to the
      Registrant’s Current Report on Form 8-K, filed on January 6, 2009 and
      incorporated herein by reference).2.3
                
                Exchange
      Agent Agreement dated January 2, 2009 by and among the Registrant,
      Computershare, Inc. and Computershare Trust Company, N.A. (previously
      filed as Exhibit 2.3 to the Registrant’s Annual Report on Form 10-K for
      the fiscal year ended December 31, 2008, filed on March 6, 2009 and
      incorporated by reference).2.4
                
                Escrow
      Agreement dated January 2, 2009 by and among the Registrant, VantagePoint
      Venture Partners IV (Q), L.P., as representative of the stockholders of
      Oxford Semiconductor, Inc., and Computershare Trust Company, N.A.
      (previously filed as Exhibit 2.4 to the Registrant’s Annual Report on Form
      10-K for the fiscal year ended December 31, 2008, filed on March 6, 2009
      and incorporated by reference).2.5
                
                Form
      of Stockholder Support Agreement dated December 15, 2008 by and among the
      Registrant, Oxford Semiconductor, Inc., VantagePoint Venture Partners IV
      (Q), L.P., as the representative of the stockholders of Oxford
      Semiconductor, Inc., and certain stockholders of the Registrant
      (previously filed as Exhibit 2.5 to the Registrant’s Annual Report on Form
      10-K for the fiscal year ended December 31, 2008, filed on March 6, 2009
      and incorporated by reference).4.1
                
                Amended
      and Restated Certificate of Incorporation of the Registrant (previously
      filed as Exhibit 3.1 to the Registrant's Registration Statement on Form
      S-1 (Registration No. 333-71795) and incorporated herein by
      reference).4.2
                
                Registrant's
      Amended and Restated Bylaws (previously filed as Exhibit 3.1 to the
      Registrant’s Current Report on Form 8-K, filed on November 26, 2007 and
      incorporated herein by reference).4.3
                
                Certificate
      of Amendment to Amended and Restated Certificate of Incorporation
      (previously filed as Exhibit 3.1 to the Registrant’s Quarterly Report on
      Form 10-Q for the quarter ended June 30, 2004 and incorporated herein by
      reference).5.1
                
                Opinion
      of Baker & McKenzie LLP (previously filed as Exhibit 5.1 to the
      Registrant’s Registration Statement on Form S-3 (Registration No.
      333-156760).23.1
                
                Consent
      of Baker & McKenzie LLP (included in Exhibit 5.1).23.2
                
                Consent
      of BDO Seidman, LLP, Independent Registered Public Accounting
      Firm.23.3
                
                Consent
      of PricewaterhouseCoopers, LLP, Independent
Accountants.24.1
                
                Power
      of Attorney (included in the signature page to this Registration
      Statement).
  24