Patent ID: 6236547
Filing Date: 2001-05-22
Classification: G05F

Abstract:
A Zener zapping device for selectively Zener-zapping a plurality of Zener diodes in a semiconductor integrated circuit having said plurality of Zener diodes connected in series and a plurality of external terminals, each of said plurality of external terminals respectively connected to one end of said series connection of said Zener diodes, to a plurality of series connection points of said series connection of said Zener diodes, and to the other end of the series connection of said Zener diodes;said Zener zapping device comprising:a single current source having one end grounded and another end connected to said external terminal corresponding to said one end of said series connection of said Zener diodes; anda plurality of switches connected in series and connected across said plurality of Zener diodes and configured to selectively make a conductive state between each of said plurality of external terminals to thereby selectively Zener zap predetermined Zener diodes using current from said single current source.