Exhibit 4.03

DESCRIPTION OF THE REGISTRANT’S SECURITIES

REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES

EXCHANGE ACT OF 1934

PDF Solutions, Inc. (“we,” “our,” “us,” or the “Company”) has one class of securities registered under Section 12 of the Securities Exchange Act of 1934, as amended: our common stock. The following summary of the terms of our common stock is based upon our Third Amended and Restated Certificate of Incorporation (“Restated Certificate”) and our Amended and Restated Bylaws (“Bylaws”). This summary does not purport to be complete and is subject to, and is qualified in its entirety by express reference to, the applicable provisions of our Restated Certificate of Incorporation and our Bylaws, which are filed as exhibits to our Annual Report on Form 10-K and are incorporated by reference herein. We encourage you to read our Restated Certificate, our Bylaws and the applicable provisions of the Delaware General Corporation Law (the “DGCL”) for more information.

DESCRIPTION OF COMMON STOCK

General

Our authorized capital stock consists of 70,000,000 shares of common stock with a par value of $0.00015 per share, and 5,000,000 shares of preferred stock with a par value of $0.00015 per share, all of which shares of preferred stock are undesignated. Our board of directors may establish the rights and preferences of the preferred stock from time to time.

Common Stock

The holders of common stock are entitled to one vote for each share held of record on all matters submitted to a vote of the stockholders. Subject to preferences that may be applicable to any outstanding preferred stock, holders of common stock are entitled to receive ratably such dividends as may be declared by the board of directors out of funds legally available for that purpose. See "Dividend Policy." In the event of our liquidation, dissolution or winding, the holders of common stock are entitled to share ratably in all assets remaining after payment of liabilities, subject to the prior distribution rights of any outstanding preferred stock. The common stock has no preemptive or conversion rights or other subscription rights. The outstanding shares of common stock are fully paid and non-assessable.

Delaware Anti-Takeover Law and Charter and Bylaw Provisions

Provisions of Delaware law and our charter documents could make our acquisition and the removal of incumbent officers and directors more difficult. These provisions are expected to discourage certain types of coercive takeover practices and inadequate takeover bids and to encourage persons seeking to acquire control of us to negotiate with us first. We believe that the benefits of increased protection of our potential ability to negotiate with the proponent of an unfriendly or unsolicited proposal to acquire or restructure us outweighs the disadvantages of discouraging such proposals because, among other things, negotiation of such proposals could result in an improvement of their terms.

We are subject to the provisions of Section 203 of the Delaware 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 that the person became an interested stockholder unless, subject to exceptions, the business combination or the transaction in which the person became an interested stockholder is approved in a prescribed manner. Generally, a "business combination" includes a merger, asset or stock sale, or other transaction resulting in a financial benefit to the stockholder. Generally, an "interested stockholder" is a person who, together with affiliates and associates, owns, or within three years prior, did own, 15% or more of the corporation's voting stock. These provisions may have the effect of delaying, deferring or preventing a change in control of us without further action by the stockholders.

Our Restated Certificate provides that stockholder action can be taken only at an annual or special meeting of stockholders and may not be taken by written consent. The Bylaws provide that special meetings of stockholders can be called only by the board of directors, the chairperson of the board, or by the president. The bylaws set forth an advance notice procedure with regard to the nomination, other than by or at the direction of the board of directors, of candidates for election as directors and with regard to business to be brought before a meeting of stockholders.

Transfer Agent and Registrar

The transfer agent and registrar for the common stock is ComputerShare Investor Services, at 250 Royall Street, Canton, MA 02021.

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