EX-4.3



 Exhibit 4.3 

APPLIED MICRO CIRCUITS CORPORATION 

2012 EMPLOYEE STOCK PURCHASE PLAN 

(as amended effective August 12, 2014) 

The following constitute the provisions of the 2012 Employee Stock Purchase Plan of Applied Micro Circuits Corporation (the “Plan”).

 1. Purpose. The purpose of the Plan is to provide employees of the Company and its Designated Subsidiaries with an opportunity to purchase Common
Stock of the Company. It is the intention of the Company to have the Plan qualify as an “Employee Stock Purchase Plan” under Section 423 of the Internal Revenue Code of 1986, as amended. The provisions of the Plan shall, accordingly,
be construed so as to extend and limit participation in a manner consistent with the requirements of that section of the Code. 
 2. Definitions.

 (a) “Board” shall mean the Board of Directors of the Company. 

(b) “Code” shall mean the Internal Revenue Code of 1986, as amended. 

(c) “Common Stock” shall mean the Common Stock of the Company. 

(d) “Company” shall mean Applied Micro Circuits Corporation, a Delaware corporation. 

(e) “Compensation” shall mean all base straight time gross earnings including payments for overtime, shift premium, sales
department commissions/bonus plan, but excluding all other bonuses and reimbursements. 
 (f) “Continuous Status as an
Employee” shall mean the absence of any interruption or termination of service as an Employee. Continuous Status as an Employee shall not be considered interrupted in the case of a leave of absence agreed to in writing by the Company,
provided that such leave is for a period of not more than 90 days or reemployment upon the expiration of such leave is guaranteed by contract or statute. 

(g) “Contributions” shall mean all amounts credited to the account of a participant pursuant to the Plan. 

(h) “Designated Subsidiaries” shall mean the Subsidiaries which have been designated by the Committee from time to time in
its sole discretion as eligible to participate in the Plan. 
 (i) “Employee” shall mean any person, including an Officer,
who is customarily employed for at least twenty (20) hours per week and more than five (5) months in a calendar year by the Company or one of its Designated Subsidiaries. 

(j) “Exchange Act” shall mean the Securities Exchange Act of 1934, as amended. 

(k) “Purchase Date” shall mean the last day of each Purchase Period of the Plan. 

(l) “Offering Date” shall mean the first business day of each Offering Period of the Plan. 

(m) “Offering Period” shall mean a period of six (6) months, commencing on February 1 and August 1 of each
year, except for the first Offering Period as set forth in Section 4(a) and as otherwise determined by the Committee with respect to any particular Offering Period. 

(n) “Officer” shall mean a person who is an officer of the Company within the meaning of Section 16 of the Exchange Act
and the rules and regulations promulgated thereunder. 
 (o) “Plan” shall mean this 2012 Employee Stock Purchase Plan. 








 (p) “Purchase Period” shall mean a period of six (6) months coinciding with
each Offering Period, including the first Purchase Period as set forth in Section 4(b). 
 (q) “Purchase Price” shall
mean an amount equal to 85% of the Fair Market Value of a share of Common Stock as defined in Section 7(b) on the Offering Date or on the Purchase Date, whichever is lower, provided, however, that, in the event (i) the Company’s
stockholders approve an increase in the number of shares available for issuance under the Plan, and (ii) all or a portion of such additional shares are to be issued with respect to one or more Offering Periods that are underway at the time of
such stockholder approval (“Additional Shares”), and (iii) the Fair Market Value of a share of Common Stock on the date of such approval (the “Approval Date Fair Market Value”) is higher than the Fair Market Value on the
Offering Date for any such Offering Period, then in such instance the Purchase Price with respect to Additional Shares shall be 85% of the Approval Date Fair Market Value or the Fair Market Value of a share of Common Stock on the Purchase Date,
whichever is lower. 
 (r) “Subsidiary” shall mean a corporation, domestic or foreign, of which not less than 50% of the
voting shares are held by the Company or a Subsidiary, whether or not such corporation now exists or is hereafter organized or acquired by the Company or a Subsidiary. In all cases, the determination of whether an entity is a Subsidiary shall be
made in accordance with Section 424(f) of the Code. 
 3. Eligibility. 

(a) Any person who is an Employee as of the Offering Date of a given Offering Period shall be eligible to participate in such Offering Period
under the Plan, subject to the requirements of Section 5(a) and the limitations imposed by Section 423(b) of the Code. 
 (b) Any
provisions of the Plan to the contrary notwithstanding, no Employee shall be granted an option under the Plan (i) if, immediately after the grant, such Employee (or any other person whose stock would be attributed to such Employee pursuant to
Section 424(d) of the Code) would own stock and/or hold outstanding options to purchase stock possessing five percent (5%) or more of the total combined voting power or value of all classes of stock of the Company or of any Subsidiary of
the Company, or (ii) if such option would permit his or her rights to purchase stock under all employee stock purchase plans (described in Section 423 of the Code) of the Company and its Subsidiaries to accrue at a rate which exceeds
Twenty-Five Thousand Dollars ($25,000) of fair market value of such stock (determined at the time such option is granted) for any calendar year in which such option is outstanding at any time. 

4. Offering Periods and Purchase Periods. 

(a) Offering Periods. The Plan shall be implemented by a series of Offering Periods with new Offering Periods commencing on or about
February 1 and August 1 of each year (or at such other time or times as may be determined by the Committee). The first Offering Period shall commence on the date that the Company’s stockholders first approve the Plan and will continue
until January 31, 2013. The Plan shall continue until terminated in accordance with Section 18 hereof. The Committee shall have the power to change the duration and/or the frequency of Offering Periods with respect to future offerings
without shareholder approval if such change is announced prior to the scheduled beginning of the first Offering Period to be affected. Eligible employees may not participate in more than one Offering Period under the Plan at a time. 

(b) Purchase Periods. Except as otherwise determined by the Committee, each Offering Period shall coincide with an identical purchase
period of six (6) months duration. The last day of each Purchase Period shall be the “Purchase Date” for such Purchase Period. A Purchase Period commencing on February 1 shall end on the next July 31. A Purchase Period
commencing on August 1 shall end on the next January 31. The first Purchase Period shall commence on the date that the Plan is first approved by the Company’s stockholders and shall end on January 31, 2013. The Committee shall
have the power to change the duration and/or frequency of Purchase Periods with respect to future purchases without shareholder approval if such change is announced prior to the scheduled beginning of the first Purchase Period to be affected. 

5. Participation. 
 (a) An eligible
Employee may become a participant in the Plan by completing a subscription agreement on the form provided by the Company and filing it with the Company’s payroll office prior to the applicable Offering Date, unless a later time for filing the
subscription agreement is set by the Committee for all eligible Employees with respect to a given offering. The subscription agreement shall set forth the percentage of the participant’s Compensation (which shall be not less than 1% and not
more than 20%) to be paid as Contributions pursuant to the Plan. 







 (b) Payroll deductions shall commence on the first payroll following the Offering Date and shall
end on the last payroll paid on or prior to the last Purchase Period of the Offering Period to which the subscription agreement is applicable, unless sooner terminated by the participant as provided in Section 10. 

6. Method of Payment of Contributions. 

(a) At the time a participant files his or her subscription agreement, the participant shall elect to have payroll deductions made on each
payday during the Offering Period in an amount not less than one percent (1%) and not more than twenty percent (20%) of such participant’s Compensation on each such payday. All payroll deductions made by a participant shall be
credited to his or her account under the Plan. A participant may not make any additional payments into such account. 
 (b) A participant
may discontinue his or her participation in the Plan as provided in Section 10, or, during the Offering Period may increase or decrease the rate of his or her Contributions during such Offering Period by completing and filing with the Company a
new subscription agreement; provided, however, that, unless otherwise provided by the Committee, no participant may effect more than one increase or decrease during a Purchase Period. The change in rate shall be effective as of the beginning of the
next pay period following the date of filing of the new subscription agreement, if the agreement is filed at least ten (10) business days prior to such date and, if not, as of the beginning of the next succeeding pay period (unless otherwise
provided by the Committee). 
 (c) Notwithstanding the foregoing, to the extent necessary to comply with Section 423(b)(8) of the Code
and Section 3(b) herein, a participant’s payroll deductions may be decreased to 0% at such time during any Offering Period as is necessary to comply with the limitations provided in such Sections. Payroll deductions shall re-commence at
the rate provided in such participant’s subscription Agreement at such time as will comply with such Sections, unless terminated by the participant as provided in Section 10. 

7. Grant of Option. 
 (a)
On the Offering Date of each Offering Period, each eligible Employee participating in such Offering Period shall be granted an option to purchase on each Purchase Date a number of shares of the Company’s Common Stock determined by dividing such
Employee’s Contributions accumulated prior to such Purchase Date and retained in the participant’s account as of the Purchase Date by the applicable Purchase Price; provided however, that the maximum number of shares an Employee may
purchase during each Purchase Period shall be 2,500 shares and provided further that such purchase shall be subject to the limitations set forth in Sections 3(b) and 13. The fair market value of a share of the Company’s Common Stock shall
be determined as provided in Section 7(b). 
 (b) The fair market value of the Company’s Common Stock on a given date shall be
determined by the Committee in its discretion based on the closing price of the Common Stock for such date (or, in the event that the Common Stock is not traded on such date, on the immediately preceding trading date), as reported by the NASDAQ
Stock Market or, if such price is not reported, the mean of the bid and asked prices per share of the Common Stock as reported by NASDAQ or, in the event the Common Stock is listed on a stock exchange, the fair market value per share shall be the
closing price on such exchange on such date (or, in the event that the Common Stock is not traded on such date, on the immediately preceding trading date), as reported in The Wall Street Journal; provided, however, that for Offering Periods
beginning on or after February 1, 2013, the fair market value of the Company’s Common Stock on the first day of each such Offering Period shall be determined by the Committee in its discretion based on the closing price of the Common Stock
on the last market trading day prior to such date, as reported by the NASDAQ Stock Market or, if such price is not reported, the mean of the bid and asked prices per share of the Common Stock as reported by NASDAQ or, in the event the Common Stock
is listed on a stock exchange, the fair market value per share shall be the closing price on such exchange on the last market trading day prior to such date, as reported in The Wall Street Journal (the “Fair Market Value”). 

8. Exercise of Option. Unless a participant withdraws from the Plan as provided in Section 10, his or her option for the purchase of shares will
be exercised automatically on each Purchase Date of an Offering Period, and the maximum number of full shares subject to the option will be purchased at the applicable Purchase Price with the accumulated Contributions in his or her account. The
shares purchased upon exercise of an option hereunder shall be deemed to be transferred to the participant on the Purchase Date. No fractional shares shall be purchased. Any payroll deductions accumulated in a participant’s account which are
not sufficient to purchase a full share shall be retained in the participant’s account for the subsequent Purchase Period or Offering Period, subject to earlier withdrawal by the participant as provided in Section 10. Any other monies left
over in a participant’s account after a Purchase Date, including amounts that would have purchased shares in excess of the maximum allowed under Section 7(a), shall be returned to the Participant. During his or her lifetime, a
participant’s option to purchase shares hereunder is exercisable only by him or her. 







 9. Delivery. As promptly as practicable after each Purchase Date of each Offering Period, the Company
shall arrange the delivery to each participant, as appropriate, of a certificate representing the shares purchased upon exercise of his or her option or the deposit of such number of shares with the broker selected by the Company for administration
of Plan stock purchases, as determined by the Company. 
 10. Voluntary Withdrawal; Termination of Employment. 

(a) A participant may withdraw all but not less than all of the Contributions credited to his or her account under the Plan at any time at
least five (5) business days (or such other time period specified by the Company) prior to each Purchase Date by giving written notice to the Company in the form provided for by the Company. All of the participant’s Contributions credited
to his or her account will be paid to him or her promptly after receipt of his or her notice of withdrawal and his or her option for the current period will be automatically terminated, and no further Contributions for the purchase of shares will be
made during the Offering Period. 
 (b) Upon termination of the participant’s Continuous Status as an Employee prior to the Purchase
Date of an Offering Period for any reason, including retirement or death, the Contributions credited to his or her account will be returned to him or her or, in the case of his or her death, to the person or persons entitled thereto under
Section 14, and his or her option will be automatically terminated. 
 (c) In the event an Employee fails to remain in Continuous
Status as an Employee of the Company for at least twenty (20) hours per week during the Offering Period in which the employee is a participant, he or she will be deemed to have elected to withdraw from the Plan and the Contributions credited to
his or her account will be returned to him or her and his or her option terminated. 
 (d) A participant’s withdrawal from an offering
will not have any effect upon his or her eligibility to participate in a succeeding offering or in any similar plan which may hereafter be adopted by the Company. 

11. Automatic Withdrawal. If the Fair Market Value of the shares on a Purchase Date during an Offering Period (other than the last Purchase Date of
such Offering Period) is less than the Fair Market Value of the shares on the Offering Date for such Offering Period, then every participant shall automatically (i) be withdrawn from such Offering Period at the close of such Purchase Date and
after the acquisition of shares for such Purchase Period, and (ii) be enrolled in the Offering Period commencing on the first business day subsequent to such Purchase Period. 

12. Interest. No interest shall accrue on the Contributions of a participant in the Plan. 

13. Stock. 
 (a) The maximum number of
shares of the Company’s Common Stock which shall be made available for sale under the Plan shall be three million eight hundred thousand (3,800,000) shares subject to adjustment upon changes in capitalization of the Company as provided in
Section 18. If the total number of shares which would otherwise be subject to options granted pursuant to Section 7(a) on the Offering Date of an Offering Period exceeds the number of shares then available under the Plan (after deduction
of all shares for which options have been exercised or are then outstanding), the Company shall make a pro rata allocation of the shares remaining available for option grant in as uniform a manner as shall be practicable and as it shall determine to
be equitable. In such event, the Company shall give written notice of such reduction of the number of shares subject to the option to each Employee affected thereby and shall similarly reduce the rate of Contributions, if necessary. 

(b) The participant will have no interest or voting right in shares covered by his or her option until such option has been exercised. 

(c) Shares to be delivered to a participant under the Plan will be registered in the name of the participant or in the name of the participant
and his or her spouse. 
 14. Administration. The Board, or a committee named by the Board (the “Committee”), shall supervise and
administer the Plan and shall have full power to adopt, amend and rescind any rules deemed desirable and appropriate for the administration of the Plan and not inconsistent with the Plan, to construe and interpret the Plan, and to make all other
determinations necessary or advisable for the administration of the Plan. The composition of the Committee shall be in 







 
accordance with the requirements to obtain or retain any available exemption from the operation of Section 16(b) of the Exchange Act pursuant to Rule 16b-3 promulgated thereunder. In
addition, the Committee may delegate administrative matters relating to the Plan to such of the Company’s officers or employees as the Committee so determines. 

15. Designation of Beneficiary. 
 (a) A
participant may file a written designation of a beneficiary who is to receive any shares and cash, if any, from the participant’s account under the Plan in the event of such participant’s death subsequent to the end of a Purchase Period
but prior to delivery to him or her of such shares and cash. In addition, a participant may file a written designation of a beneficiary who is to receive any cash from the participant’s account under the Plan in the event of such
participant’s death prior to the Purchase Date of an Offering Period. If a participant is married and the designated beneficiary is not the spouse, spousal consent shall be required for such designation to be effective. 

(b) Such designation of beneficiary may be changed by the participant (and his or her spouse, if any) at any time by written notice. In the
event of the death of a participant and in the absence of a beneficiary validly designated under the Plan who is living at the time of such participant’s death, the Company shall deliver such shares and/or cash to the executor or administrator
of the estate of the participant, or if no such executor or administrator has been appointed (to the knowledge of the Company), the Company, in its discretion, may deliver such shares and/or cash to the spouse or to any one or more dependents or
relatives of the participant, or if no spouse, dependent or relative is known to the Company, then to such other person as the Company may designate. 
 16.
Transferability. Neither Contributions credited to a participant’s account nor any rights with regard to the exercise of an option or to receive shares under the Plan may be assigned, transferred, pledged or otherwise disposed of in any
way (other than by will, the laws of descent and distribution, or as provided in Section 15) by the participant. Any such attempt at assignment, transfer, pledge or other disposition shall be without effect, except that the Company may treat
such act as an election to withdraw funds in accordance with Section 10. 
 17. Use of Funds. The Company may use all Contributions received or
held by the Company under the Plan for any corporate purpose, and the Company shall not be obligated to segregate such Contributions. 
 18. Adjustments
Upon Changes in Capitalization; Corporate Transactions. 
 (a) Adjustment. Subject to any required action by the shareholders of
the Company, the number of shares of Common Stock covered by each option under the Plan which has not yet been exercised and the number of shares of Common Stock which have been authorized for issuance under the Plan but have not yet been placed
under option (collectively, the “Reserves”), as well as the price per share of Common Stock covered by each option under the Plan which has not yet been exercised, shall be proportionately adjusted for any increase or decrease in the
number of issued shares of Common Stock resulting from a stock split, reverse stock split, stock dividend, combination or reclassification of the Common Stock, or any other increase or decrease in the number of shares of Common Stock effected
without receipt of consideration by the Company; provided, however, that conversion of any convertible securities of the Company shall not be deemed to have been “effected without receipt of consideration”. Such adjustment shall be made by
the Committee, whose determination in that respect shall be final, binding and conclusive. Except as expressly provided herein, no issue by the Company of shares of stock of any class, or securities convertible into shares of stock of any class,
shall affect, and no adjustment by reason thereof shall be made with respect to, the number or price of shares of Common Stock subject to an option. 

(b) Corporate Transactions. In the event of the proposed dissolution or liquidation of the Company, the Offering Period will terminate
immediately prior to the consummation of such proposed action, unless otherwise provided by the Committee. In the event of a proposed sale of all or substantially all of the assets of the Company, or the merger of the Company with or into another
corporation, each option under the Plan shall be assumed or an equivalent option shall be substituted by such successor corporation or a parent or subsidiary of such successor corporation, unless the Committee determines, in the exercise of its sole
discretion and in lieu of such assumption or substitution, to shorten the Offering Period then in progress by setting a new Purchase Date (the “New Purchase Date”). If the Committee shortens the Offering Period then in progress in lieu of
assumption or substitution in the event of a merger or sale of assets, the Committee shall notify each participant in writing, at least ten (10) days prior to the New Purchase Date, that the Purchase Date for his or her option has been changed
to the New Purchase Date and that his or her option will be exercised automatically on the New Purchase Date, unless prior to such date he or she has withdrawn from the Offering Period as provided in Section 10. For purposes of this paragraph,
an option granted under the Plan shall be deemed to be assumed if, following the sale of assets or merger, the option confers the right to purchase, for each share of option stock subject to the option immediately prior to the sale of assets or
merger, the consideration (whether stock, cash or other securities or 







 
property) received in the sale of assets or merger by holders of Common Stock for each share of Common Stock held on the effective date of the transaction (and if such holders were offered a
choice of consideration, the type of consideration chosen by the holders of a majority of the outstanding shares of Common Stock); provided, however, that if such consideration received in the sale of assets or merger was not solely common stock of
the successor corporation or its parent (as defined in Section 424(e) of the Code), the Committee may, with the consent of the successor corporation and the participant, provide for the consideration to be received upon exercise of the option
to be solely common stock of the successor corporation or its parent equal in fair market value to the per share consideration received by holders of Common Stock and the sale of assets or merger. 

The Committee may, if it so determines in the exercise of its sole discretion, also make provision for adjusting the Reserves, as well as the
price per share of Common Stock covered by each outstanding option, in the event that the Company effects one or more reorganizations, recapitalizations, rights offerings or other increases or reductions of shares of its outstanding Common Stock,
and in the event of the Company being consolidated with or merged into any other corporation. 
 19. Amendment or Termination. 

(a) The Committee may at any time and for any reason terminate or amend the Plan. Except as provided in Section 18, no such termination
may affect options previously granted, provided that an Offering Period may be terminated by the Committee on a Purchase Date if the Committee determines that the termination of the Plan is in the best interests of the Company and the shareholders
or if continuation of an Offering Period would cause the Company to incur adverse accounting charges resulting from a change in the generally accepted accounting rules applicable to such plans. Except as provided in Section 18, no amendment may
make any change in any option theretofore granted which adversely affects the rights of any participant. In addition, to the extent necessary to comply with Rule 16b-3 under the Exchange Act, or under Section 423 of the Code (or any successor
rule or provision or any applicable law or regulation), the Company shall obtain shareholder approval in such a manner and to such a degree as so required. 

(b) Without shareholder consent and without regard to whether any participant rights may be considered to have been adversely affected, the
Committee shall be entitled to change the Offering Periods and Purchase Periods, limit the frequency and/or number of changes in the amount withheld during an Offering Period, establish the exchange ratio applicable to amounts withheld in a currency
other than U.S. dollars, permit payroll withholding in excess of the amount designated by a participant in order to adjust for delays or mistakes in the Company’s processing of properly completed withholding elections, establish reasonable
waiting and adjustment periods and/or accounting and crediting procedures to ensure that amounts applied toward the purchase of Common Stock for each participant properly correspond with amounts withheld from the participant’s Compensation, and
establish such other limitations or procedures as the Committee determines in its sole discretion advisable which are consistent with the Plan. 
 20.
Notices. All notices or other communications by a participant to the Company under or in connection with the Plan shall be deemed to have been duly given when received in the form specified by the Company at the location, or by the person,
designated by the Company for the receipt thereof. 
 21. Conditions Upon Issuance of Shares. Shares shall not be issued with respect to an option
unless the exercise of such option and the issuance and delivery of such shares pursuant thereto shall comply with all applicable provisions of law, domestic or foreign, including, without limitation, the Securities Act of 1933, as amended, the
Exchange Act, the rules and regulations promulgated thereunder, and the requirements of any stock exchange upon which the shares may then be listed, and shall be further subject to the approval of counsel for the Company with respect to such
compliance. As a condition to the exercise of an option, the Company may require the person exercising such option to represent and warrant at the time of any such exercise that the shares are being purchased only for investment and without any
present intention to sell or distribute such shares if, in the opinion of counsel for the Company, such a representation is required by any of the aforementioned applicable provisions of law. 

22. Term of Plan; Effective Date. The Plan shall become effective upon the earlier to occur of its adoption by the Board or its approval by the
shareholders of the Company. It shall continue in effect for a term of twenty (20) years unless sooner terminated under Section 19. 
 23.
Additional Restrictions of Rule 16b-3. The terms and conditions of options granted hereunder to, and the purchase of shares by, persons subject to Section 16 of the Exchange Act shall comply with the applicable provisions of Rule 16b-3.
This Plan shall be deemed to contain, and such options shall contain, and the shares issued upon exercise thereof shall be subject to, such additional conditions and restrictions as may be required by Rule 16b-3 to qualify for the maximum exemption
from Section 16 of the Exchange Act with respect to Plan transactions. 







 24. Not a Contract of Employment. The adoption and maintenance of the Plan shall not be deemed to be a
contract between the Company or any Designated Subsidiaries and any person or to be consideration for the employment of any person. Participation in the Plan at any given time shall not be deemed to create the right to participate in the Plan, or
any other arrangement permitting an employee of the Company or any Designated Subsidiaries to purchase Common Stock at a discount, in the future. The rights and obligations under any participant’s terms of employment with the Company or any of
the Designated Subsidiaries shall not be affected by participation in the Plan. Nothing herein contained shall be deemed to give any person the right to be retained in the employ of the Company or any of the Designated Subsidiaries or to restrict
the right of the Company or any of the Designated Subsidiaries to discharge any person at any time, nor shall the Plan be deemed to give the Company or any of the Designated Subsidiaries the right to require any person to remain in the employ of the
Company or any of the Designated Subsidiaries or to restrict any person’s right to terminate his employment at any time. The Plan shall not afford any participant any additional right to compensation as a result of the termination of such
participant’s employment for any reason whatsoever. 
 25. Equal Rights and Privileges. All eligible employees shall have equal rights and
privileges with respect to the Plan so that the Plan qualifies as an “employee stock purchase plan” within the meaning of Section 423 of the Code and the related Treasury regulations. Any provision of the Plan which is inconsistent
with Section 423 of the Code shall without further act or amendment by the Company or the Board be reformed to comply with the requirements of Section 423. This Section shall take precedence over all other provisions of the Plan.