Exhibit 23.1 CONSENT OF INDEPENDENT ACCOUNTANTS We hereby consent to the incorporation by reference in the Registration Statements on Form S-8 (Nos. 333-69594, 333-47606 and 333-43691) of Supertex, Inc. of our report dated April 25, 2003 relating to the financial statements and financial statement schedule, which appears in this Form 10-K. San Jose, California June 23, 2003