EXHIBIT 2.5


STOCKHOLDER
SUPPORT AGREEMENT
 THIS
STOCKHOLDER SUPPORT AGREEMENT (this “Agreement”) is made
as of December 15, 2009, by and among PLX Technology, Inc., a Delaware
corporation (the “Purchaser”), Oxford
Semiconductor, Inc., a Delaware corporation (the “Company”),
VantagePoint Venture Partners IV (Q), L.P., a Delaware limited partnership, not
individually, but solely in its capacity as the representative of the
stockholders of the Company (the “Company Stockholder
Representative”), and each of the stockholders of the Purchaser whose
names appear on the signature pages of this Agreement (each, a “Purchaser
Stockholder” and, collectively, the “Purchaser
Stockholders”).
  RECITALS
 WHEREAS,
concurrently with the execution of this Agreement, the Purchaser, PLX
Technology, Inc., a Delaware corporation and a wholly owned subsidiary of the
Purchaser (“Merger
Sub”), the Company and the Company Stockholder Representative, have
entered into an Agreement and Plan of Merger (the “Merger Agreement”),
which provides for the merger of Merger Sub with and into the Company (the
“Merger”);
  WHEREAS,
pursuant to the Merger, all of the issued and outstanding shares of capital
stock of the Company will be canceled and converted into the right to receive
the consideration set forth in the Merger Agreement upon the terms and subject
to the conditions set forth in the Merger Agreement;
  WHEREAS,
a portion of the consideration for the Merger consists of a promissory note (the
“Note”) in the
aggregate principal amount of $14,200,000 to be issued by the Purchaser to the
Company Stockholder Representative on behalf of the stockholders of the Company
in accordance with the terms of the Merger Agreement;
  WHEREAS,
Section 2.1(d) of the Merger Agreement contemplates that the principal amount of
the Note will be satisfied by the delivery of 3,400,000 shares of common stock
of the Purchaser (the “Note Satisfaction
Shares”) upon approval by the Purchaser’s stockholders of the issuance of
the Note Satisfaction Shares (the “Note Satisfaction
Proposal”);
  WHEREAS,
as of the date hereof, each Purchaser Stockholder Beneficially Owns (as defined
below) the number of Purchaser Shares (as defined below) as set forth on Exhibit A of this
Agreement; and
  WHEREAS,
as a further inducement to the Company to execute the Merger Agreement, the
Purchaser Stockholders and the Purchaser agree to vote the Purchaser Shares as
provided in this Agreement, and the execution and delivery of this
Agreement is a material condition to the Company’s willingness to enter
into the Merger Agreement.
  NOW,
THEREFORE, the parties hereto hereby agree as follows:
  1.  Certain
Definitions.  Capitalized terms not defined herein have the
meanings ascribed to them in the Merger Agreement.  For purposes of
this Agreement:
  (a)  A Person
will be deemed to “Beneficially Own” a
security if such Person has “beneficial ownership” of such securities as
determined pursuant to Rule 13d-3 under the Securities Exchange Act of
1934, as amended.
  (b)  “Expiration Date”
means the earlier to occur of (i) such date and time as the Merger
Agreement is validly terminated pursuant to Article 8 thereof and (ii) the date
that the Purchaser Stockholders vote on or consent to the Note Satisfaction
Proposal whether or not at the Special Meeting (or the date of adjournment or
postponement thereof, as applicable).
  (c)  “Options” means, with
respect to each Purchaser Stockholder as follows: (i) all securities
Beneficially Owned by such Purchaser Stockholder as of the date of this
Agreement that are convertible into, or exercisable or exchangeable for, shares
of capital stock of the Purchaser, including, without limitation, options,
warrants and other rights to acquire shares of Purchaser Common Stock or other
shares of capital stock of the Purchaser; and (ii) all securities of which
such Purchaser Stockholder acquires Beneficial Ownership during the period from
the date of this Agreement through and including the Expiration Date that are
convertible into, or exercisable or exchangeable for, shares of capital stock of
the Purchaser, including, without limitation, options, warrants and other rights
to acquire shares of Purchaser Common Stock or other shares of capital stock of
the Purchaser.
  (d)  “Purchaser Shares”
means, with respect to each Purchaser Stockholder as
follows:  (i) all shares of capital stock of the Purchaser
Beneficially Owned by such Purchaser Stockholder as of the date of this
Agreement; and (ii) all shares of capital stock of the Purchaser of which
such Purchaser Stockholder acquires Beneficial Ownership during the period from
the date of this Agreement through and including the Expiration Date, including,
without limitation, in each case, shares issued upon the conversion, exercise or
exchange of Options.
  2.  No Transfer of Voting
Rights.  Each Purchaser Stockholder agrees that, during the
period from the date of this Agreement through and including the Expiration
Date, such Purchaser Stockholder will not directly or indirectly transfer any
Purchaser Shares, will not deposit (or cause or permit the deposit of) any
Purchaser Shares or Options into a voting trust or grant (or cause or permit the
grant of) any proxy or enter into (or cause or permit the entry into) any voting
agreement or similar agreement with respect to any of the Purchaser Shares or
Options other than the proxy granted by each Purchaser Stockholder pursuant to
Section 4 hereof and as contemplated by this Agreement. Notwithstanding the
foregoing, a Purchaser Stockholder may transfer any Purchaser Shares pursuant to
Rule 10b5-1 trading plans entered into prior to the date of this
Agreement.
  3.  Agreement to Vote Purchaser
Shares.
  (a)  Each
Purchaser Stockholder will vote at the Special Meeting, or the adjournment or
postponement thereof, or consent to the following, to the extent not voted by
the Person(s) appointed under the proxy granted under Section 4 hereof, all of
the Purchaser Shares or cause the Purchaser Shares to be voted:
  (i)  in favor
of (A) the Note Satisfaction Proposal and (B) any other actions
presented to the holders of capital stock of the Purchaser in furtherance of the
Note Satisfaction Proposal;
  (ii)  against
approval of any proposal made in opposition to, or in competition with, the Note
Satisfaction Proposal; and
  (iii)  against
any other action that would interfere with or impede the Note Satisfaction
Proposal or issuance or reservation of a sufficient number of shares of
Purchaser common stock for the satisfaction of the Note as contemplated in
Section 2.1(d) of the Merger Agreement.
  (b)  No
Purchaser Stockholder will enter into any agreement or understanding with any
Person to vote, consent or give instructions in any manner inconsistent with
this Section 3.
  4.  Irrevocable
Proxy.
  (a)  Each
Purchaser Stockholder hereby irrevocably (to the fullest extent permitted by
law) appoints the Purchaser, and any designee of the Purchaser, and each of them
individually, as the sole and exclusive attorneys-in-fact and proxies of such
Purchaser Stockholder with full power of substitution and resubstitution, at any
time after the date hereof and through and including the Expiration Date to vote
and exercise all voting rights with respect to, and to grant a consent or
approval in respect of (in each case, to the full extent that such Purchaser
Stockholder is entitled to do so), all of the Purchaser Shares (including,
without limitation, the power to execute and deliver written consents), at the
Special Meeting or otherwise with respect to the matters described in and in
accordance with Section 3 hereof.  THIS PROXY AND POWER OF ATTORNEY IS
IRREVOCABLE AND COUPLED WITH AN INTEREST THROUGHOUT THE TERM
HEREOF.  Upon the execution of this Agreement by each Purchaser
Stockholder, such Purchaser Stockholder hereby revokes any and all prior proxies
or powers of attorney given by such Purchaser Stockholder with respect to voting
of or granting consent with respect to the Purchaser Shares on the matters
referred to in Section 3 and agrees not to grant any subsequent proxies or
powers of attorney with respect to the voting of or granting consent with
respect to the Purchaser Shares on the matters referred to in Section 3
until after the termination of this Agreement.  Each Purchaser
Stockholder understands and acknowledges that the Company is entering into the
Merger Agreement in reliance upon the Purchaser Stockholders’ execution and
delivery of this Agreement and the Purchaser Stockholders’ granting of the
proxies contained in this Section 4.  Each Purchaser Stockholder
hereby affirms that the proxy granted in this Section 4 is given in
connection with the execution of the Merger Agreement, and that such proxy is
given to secure the performance of the duties of such Purchaser Stockholder
under this Agreement.  Each Purchaser Stockholder agrees to execute
any further agreement or form reasonably necessary to confirm and effectuate the
grant of the proxy contained herein.  All authority conferred pursuant
to this Section 4 and otherwise in this Agreement shall survive the death or
incapacity of the Purchaser Stockholder.
  (b)  Purchaser,
and any designee of the Purchaser, as the sole and exclusive attorneys-in-fact
and proxies of the Purchaser Stockholders pursuant to Section 4(a) hereof,
hereby irrevocably agree to vote and exercise all voting rights with respect to,
and to grant a consent or approval in respect of (in each case, to the full
extent that such Purchaser and any designee of Purchaser is entitled to do so),
all of the Purchaser Shares (including, without limitation, the power to execute
and deliver written consents), at the Special Meeting or otherwise with respect
to the matters described in and in accordance with Section 3
hereof.
  5.  Representations, Warranties
and Covenants of the Purchaser Stockholders.  As of the date
hereof, each Purchaser Stockholder represents, warrants and covenants to the
Company as follows:
  (a)  Such
Purchaser Stockholder is the Beneficial Owner of the Purchaser Shares and the
Options as set forth on the Exhibit A to this
Agreement.
  (b)  Such
Purchaser Stockholder does not Beneficially Own any shares of capital stock of
the Purchaser or any securities convertible into, or exchangeable or exercisable
for, shares of capital stock of the Purchaser, other than the Purchaser Shares
and Options set forth on Exhibit A
hereto.
  (c)  Such
Purchaser Stockholder has the full power to dispose, vote or direct the voting
of the Purchaser Shares for and on behalf of all beneficial owners of the
Purchaser Shares.
  (d)  The
Purchaser Shares are, and at all times up to and including the Expiration Date
will be, Beneficially Owned by such Purchaser Stockholder, free and clear of any
rights of first refusal, co-sale rights, security interests, liens, pledges,
options, charges, proxies, voting trusts or agreements, or any other
encumbrances of any kind or nature.
  (e)  The
execution and delivery of this Agreement by such Purchaser Stockholder do not,
and such Purchaser Stockholder’s performance of its obligations under this
Agreement will not conflict with, violate, result in a breach of, or result in
the creation of any lien or encumbrance (other than by virtue of this Agreement)
on the Purchaser Shares and Options, or require any consent, approval or notice
under, any order, decree, judgment, statute, law, rule, regulation or agreement
or other arrangement applicable to such Purchaser Stockholder or by which such
Purchaser Stockholder or any of such Purchaser Stockholder’s properties or
assets, including, without limitation, the Purchaser Shares and Options, is
bound.  The execution and delivery of this Agreement constitutes a
valid binding agreement of the Purchaser Stockholder enforceable in accordance
with its terms.
  (f)  Such
Purchaser Stockholder has full power and authority to make, enter into and carry
out the terms of this Agreement with respect to all of the Purchaser Shares
without limitation, qualification or restriction on such power and
authority.
  (g)  The
failure of the spouse, if any, of such Purchaser Stockholder to be a party or
signatory to this Agreement will not (i) prevent such Purchaser Stockholder from
performing such Purchaser Stockholder's obligations hereunder or (ii) prevent
this Agreement from constituting the legal, valid and binding obligation of such
Purchaser Stockholder in accordance with its terms.
  6. Consents and
Waivers.  Each Purchaser Stockholder hereby gives all consents
and waivers that may be required from it for the execution and delivery of this
Agreement under the terms of any agreement or instrument to which such Purchaser
Stockholder is a party or subject or in respect of any rights such Purchaser
Stockholder may have.
  7.  Termination.  This
Agreement will terminate and will have no further force or effect as of the
Expiration Date.
  8.  Purchaser Stockholder
Capacity.  So long as a Purchaser Stockholder remains an
officer or director of the Purchaser, nothing in this Agreement will be
construed as preventing, limiting or otherwise affecting any actions taken (or
not taken) by such Purchaser Stockholder in his or her capacity as an officer or
director of the Purchaser or any of its Subsidiaries or from fulfilling the
obligations of such office (including, without limitation, the performance of
obligations required by the fiduciary obligations of such Purchaser Stockholder
acting solely in his or her capacity as an officer or director).
  9.  Miscellaneous.
  (a)  Waiver.  No
failure on the part of any party to exercise any power, right, privilege or
remedy under this Agreement, and no delay on the part of any party in exercising
any power, right, privilege or remedy under this Agreement, will operate as a
waiver of such power, right, privilege or remedy; and no single or partial
exercise of any such power, right, privilege or remedy will preclude any other
or further exercise thereof or of any other power, right, privilege or
remedy.  The Company will not be deemed to have waived any claim
arising out of this Agreement, or any power, right, privilege or remedy under
this Agreement, unless the waiver of such claim, power, right, privilege or
remedy is expressly set forth in a written instrument duly executed and
delivered on behalf of the Company; and any such waiver will not be applicable
or have any effect except in the specific instance in which it is
given.
  (b)  Notices.  All
notices and other communications under this Agreement must be in writing and are
deemed duly delivered when (i) delivered if delivered personally or by
nationally recognized overnight courier service (costs prepaid), (ii) sent by
facsimile with confirmation of transmission by the transmitting equipment (or,
the first Business Day following such transmission if the date of transmission
is not a Business Day) or (iii) received or rejected by the addressee within
five Business Days of dispatch, if sent by certified mail, return receipt
requested; in each case to the following addresses or facsimile numbers and
marked to the attention of the individual (by name or title) designated below
(or to such other address, facsimile number or individual as a party may
designate by notice to the other parties):
  (i)  if to the
Purchaser, to:
  PLX
Technology, Inc.
 870 Maude
Avenue
 Sunnyvale
CA 94085
 Attention:        
Chief Financial Officer
 Facsimile:         
(408) 774-2169
  with a
copy (which will not constitute notice) to:
  Baker
& McKenzie LLP
 Two
Embarcadero Center, Ste. 1100
 San
Francisco, CA  94111-3909
 Attention:        
Stephen J. Schrader
 Facsimile:          (415)
576-3099
  Baker
& McKenzie LLP
 660
Hansen Way
 Palo
Alto, CA  94304-0309
 Attention:        
Matthew R. Gemello
 Facsimile:          (650)
856-9299
  (ii)  if to the
Company, to:
  Oxford
Semiconductor, Inc.
 1900
McCarthy Drive
 Milpitas,
CA 95035
 Attention:        
Chief Financial Officer
 Facsimile:          (408)
942-7245
  with a
copy (which will not constitute notice) to:
  Orrick
Herrington, Sutcliffe. LLP
 The
Orrick Building
 405
Howard Street
 San
Francisco, California  94105
 Attention:        
Richard V. Smith
  Facsimile:          (415)
773-5759
  (iii)  if to the
Company Stockholder Representative, to:
  VantagePoint
Venture Partners IV (Q), L.P
 1001
Bayhill Drive, Suite 300
 San
Bruno, CA 94066
 Attention:        
General Counsel
 Facsimile:         
(650) 869-6078
  (iv)  if to the
Purchaser Stockholders: To the address of the Purchaser as set forth
above.
  (c)  Counterparts.  This
Agreement may be executed in two or more counterparts, all of which will be
considered one and the same agreement and will become effective when one or more
counterparts have been signed by each of the parties and delivered to the other
parties, it being understood that all parties need not sign the same
counterpart.
  (d)  Entire Agreement;
Amendment.  This Agreement (including any schedules and
exhibits hereto) constitutes the entire agreement among the parties and
supersedes any prior understandings, agreements or representations by or among
the parties, or any of them, written or oral, with respect to the subject matter
of this Agreement.  This Agreement may not be amended, supplemented or
otherwise modified except in a written document signed by each party to be bound
by the amendment and that identifies itself as an amendment to this
Agreement.
  (e)  Severability.  If
any provision of this Agreement is held invalid, illegal or unenforceable, the
validity, legality and enforceability of the remaining provisions of this
Agreement are not affected or impaired in any way and the parties agree to
negotiate in good faith to replace such invalid, illegal and unenforceable
provision with a valid, legal and enforceable provision that achieves, to the
greatest lawful extent under this Agreement, the economic, business and other
purposes of such invalid, illegal or unenforceable provision.
  (1)  Governing Law;
Disputes.  The internal laws of the State of Delaware (without
giving effect to any choice or conflict of law provision or rule (whether of the
State of Delaware or any other jurisdiction) that would cause the application of
laws of any other jurisdiction) govern all matters arising out of or relating to
this Agreement and its exhibits and all of the transactions it contemplates,
including its validity, interpretation, construction, performance and
enforcement and any disputes or controversies arising therefrom.  In
the event of a dispute, Section 10.11 of the Merger Agreement will
govern.  EACH OF THE PARTIES HERETO EXPRESSLY WAIVES AND FOREGOES THE
RIGHT TO A JURY TRIAL IN CONNECTION WITH ANY SUIT, ACTION OR PROCEEDING SEEKING
ENFORCEMENT OF SUCH PARTY’S RIGHTS UNDER THIS AGREEMENT OR ANY AGREEMENT OR
INSTRUMENT CONTEMPLATED HEREBY OR THEREBY OR ENTERED INTO IN CONNECTION HEREWITH
OR THEREWITH OR ANY OF THE TRANSACTIONS CONTEMPLATED HEREBY OR
THEREBY.
  (f)  Further
Assurances.  Each party to this Agreement will do and perform
or cause to be done and performed all such further acts and things and will
execute and deliver all such other agreements, certificates, instruments and
documents as the other party hereto may reasonably request in order to carry out
the intent and accomplish the purposes of this Agreement.
  (g)  Interpretation.  The
language used in this Agreement is the language chosen by the parties to express
their mutual intent, and no provision of this Agreement will be interpreted for
or against any party because that party or its attorney drafted the
provision.
  (h)  Remedies.  The
parties agree that irreparable damage would occur in the event that any of the
provisions of this Agreement were not performed in accordance with their
specific terms or were otherwise breached.  The parties accordingly
agree that, in addition to any other remedy to which they are entitled at law or
in equity, the parties are entitled to injunctive relief to prevent breaches of
this Agreement and otherwise to enforce specifically the provisions of this
Agreement.  Each party expressly waives any requirement that any other
party obtain any bond or provide any indemnity in connection with any action
seeking injunctive relief or specific enforcement of the provisions of this
Agreement.
  (i)  Binding Effect; No
Assignment.  This Agreement and all of the provisions hereof
will be binding upon and inure to the benefit of the parties hereto and their
respective heirs, successors and permitted assigns, but, except as otherwise
specifically provided herein, neither this Agreement nor any of the rights,
interests or obligations of the parties hereto may be assigned by any of the
parties without the prior written consent of the other parties.  Any
purported assignment in violation of this Section 9(i) will be
void.
 IN
WITNESS WHEREOF, the undersigned have executed this Stockholder Support
Agreement on the date first above written.
  “Purchaser”
                  
                  PLX
      TECHNOLOGY, INC., a Delaware corporation
                  
                  
                  By:          /s/
      Ralph H. Schmitt
                  Name:    
      Ralph H.
      Schmitt
                  Title:       Chief
      Executive
      Officer
                “Company”
                  
                  OXFORD
      SEMICONDUCTOR, INC., a Delaware corporation
                  
                  
                  By:          /s/
      William J. Schroeder
                  Name:    
      William J.
      Schroeder
                  Title:       President
      and Chief Executive
      Officer“Company Stockholder
      Representative”
                  
                  VantagePoint
      Venture Partners IV (Q), L.P., solely for purposes related to the Company
      Stockholder Representative as set forth herein
                  
                  By:          /s/
      Alan E. Salzman
                  Name:    
      Alan E.
      Salzman
                  Title:       Managing
      Member“Directors and
      Officers”
                  
                  By:          /s/
      Ralph H. Schmitt
                  Name:    
      Ralph H. Schmitt
                  Title:       President,
      Chief Executive Officer andDirector
                  
                  
                  By:          /s/
      Arthur O. Whipple
                  Name:    
      Arthur O. Whipple
                  Title:      
      Chief Financial Officer, Vice President –Finance and
Secretary
                  
                  
                  By:          /s/
      Larry Chisvin
                  Name:    
      Lawrence Chisvin
                  Title:       Chief
      Operating Officer
                By:          /s/
      Michael Salameh
                  Name:    
      Michael Salameh
                  Title:       Director
                  
                  
                  By:          /s/
      John Hart
                  Name:    
      John Hart
                  Title:       Director
                  
                  
                  By:          /s/
      Robert Smith
                  Name:    
      Robert Smith
                  Title:       Director
                  
                  
                  By:          /s/
      Thomas Riordan
                  Name:    
      Thomas Riordan
                  Title:       Director
                  
                  
                  By:          /s/
      Patrick Verderico
                  Name:    
      Patrick Verderico
                  Title:       Director