Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number: 3235-0287
Expires: January 31, 2005
Estimated average burden hours per response... 0.5

(Print or Type Responses)
1. Name and Address of Reporting Person *
HARTGRING CORNELIS
   2. Issuer Name and Ticker or Trading Symbol
PDF SOLUTIONS INC [PDFS] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Vice President, CSS
(Last)
(First)
(Middle)
333 W. SAN CARLOS ST., SUITE 1000		 3. Date of Earliest Transaction (Month/Day/Year)
02/16/2017
(Street)

SAN JOSE, CA 95110		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 02/16/2017   M   10,855 A (1) 47,441 (2) D  
Common Stock 02/16/2017   S   17,952 D (3) 29,489 D  
Common Stock 02/17/2017   S   981 D (4) 28,508 D  

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number. SEC 1474 (9-02)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Stock Options (Right to Buy) $ 6.21 02/16/2017   M     1,688   (5) 05/26/2021 Common Stock 1,688 $ 6.21 0 D  
Stock Options (Right to Buy) $ 8.79 02/16/2017   M     2,500   (6) 05/22/2022 Common Stock 2,500 $ 8.79 0 D  
Stock Options (Right to Buy) $ 8.79 02/16/2017   M     6,667   (7) 05/22/2022 Common Stock 6,667 $ 8.79 0 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
HARTGRING CORNELIS
333 W. SAN CARLOS ST.
SUITE 1000
SAN JOSE, CA 95110		       Vice President, CSS  

Signatures

 /s/ Gregory Walker, Attorney-in-Fact for Cornelis Hartgring   02/21/2017
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Includes exercise of fully vested stock options grants awarded to the Reporting person on May 22, 2011 and on May 22, 2012
(2) Includes 1,561 shares of common stock that were purchased on January 31, 2017 under the PDF Employee Stock Purchase Plan
(3) Average weighted sale price for shares disposed of in the reported transaction. The shares were sold in multiple brokers' transactions at various market prices per share ranging from $22.00 to $22.52.
(4) Average weighted sale price for shares disposed of in the reported transaction. The shares were sold in multiple brokers' transactions at various market prices per share ranging from $22.134 to $22.1596.
(5) Earliest vesting date of the stock options granted on May, 27, 2011 was June 27, 2011 with 1/48th of the total shares vesting monthly until fully vested on June 27, 2014.
(6) 1/4th of the total number of shares subject to option vested on May 22, 2012 and 1/4th of the total shares vested each anniversary of the grant date, fully vested on May 22, 2015.
(7) Earliest vesting date of the total stock options granted on May 22, 2012 was June 22, 2012 1/48th of the total shares vesting monthly until fully vested on June 22, 2016.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.