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
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(Print or Type Responses)
1. Name and Address of Reporting Person *
Caulfield Thomas
   2. Issuer Name and Ticker or Trading Symbol
PDF SOLUTIONS INC [PDFS] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
333 WEST SAN CARLOS STREET, SUITE 700		 3. Date of Earliest Transaction (Month/Day/Year)
08/18/2008
(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

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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
2001 Stock Plan Option (right to buy) $ 12.98 08/18/2008   D     30,000   (1) 08/29/2016 Common Stock 30,000 $ 0 (2) 0 D  
2001 Stock Plan Option (right to buy) $ 10.43 08/18/2008   D     15,000   (3) 05/29/2017 Common Stock 15,000 $ 0 (4) 0 D  
Restricted Stock Right (5) 08/18/2008   A   7,143     (6)   (6) Common Stock 7,143 (2) 7,143 D  
Restricted Stock Right (5) 08/18/2008   A   3,572     (6)   (6) Common Stock 3,572 (4) 3,572 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Caulfield Thomas
333 WEST SAN CARLOS STREET
SUITE 700
SAN JOSE, CA 95110		   X      

Signatures

 /s/ P. Steven Melman, Attorney-in-Fact for Thomas Caulfield   08/20/2008
**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) The cancelled option provided for vesting as follows: 12/48ths of the total shares subject to the option vested on September 15, 2007 and 1/48th of the total shares vested on the 15th day of each month thereafter, subject to the reporting person's continued service with PDF Solutions, Inc., or an eligible affiliate thereof, through each vesting date and subject to accelerated vesting in certain circumstances.
(2) Pursuant to PDF Solutions, Inc.'s offer to exchange described in Schedule TO-1 filed on June 10, 2008, as amended (the "Exchange Offer") on August 18, 2008, PDF Solutions, Inc. cancelled an option granted to the reporting person on September 16, 2006. In exchange for the option, the reporting person received 7,143 restricted stock rights.
(3) The cancelled option provided for vesting as follows: 12/48ths of the total shares subject to the option vested on May 30, 2008 and 1/48th of the total shares vested on the 30th day of each month thereafter, subject to the reporting person's continued service with PDF Solutions, Inc. or an eligible affiliate thereof, through each vesting date and subject to accelerated vesting in certain circumstances.
(4) Pursuant to the Exchange Offer, on August 18, 2008, PDF Solutions, Inc. cancelled an option granted to the reporting person on May 27, 2008. In exchange for the option, the reporting person received 3,572 restricted stock rights.
(5) Each restricted stock right ("RSR") represents a bookkeeping entry equal in value to one (1) share of common stock of PDF Solutions, Inc.
(6) 12.5% of the total number of rights will vest on May 15, 2009 and 12.5% will vest every six (6) months thereafter, subject to the reporting person's continued service with PDF Solutions, Inc., or an eligible affiliate thereof, through each vesting date and subject to accelerated vesting in certain circumstances. The RSR will be automatically settled in shares upon vesting of the RSR.

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