Patent ID: 6483318
Filing Date: 2002-11-19
Classification: G01R

Abstract:
A circuit for providing a selectable short between a pair of electrical nodes selected from a plurality of pairs of electrical nodes, comprising:a) a multiplexer circuit having a first terminal electrically coupled to a first node of a first pair of said nodes, a second terminal electrically coupled to a second node of said first pair of said nodes, a third terminal electrically coupled to a first node of a second pair of said nodes, a fourth terminal electrically coupled to a second node of said second pair of said nodes, a fifth terminal, a sixth terminal, a seventh terminal, and an eighth terminal; b) a differential voltage amplifier circuit having a first input terminal electrically coupled to said fifth terminal of said multiplexer circuit, a second input terminal electrically coupled to said sixth terminal of said multiplexer circuit, and an output terminal; c) a first current output differential amplifier circuit having a first input terminal electrically coupled to said output terminal of said differential voltage amplifier circuit, a second input terminal held at a predetermined voltage level, and an output terminal electrically coupled to said seventh terminal of said multiplexer circuit; and d) a second current output differential amplifier circuit having a first input terminal electrically coupled to said output terminal of said differential voltage amplifier circuit, a second input terminal held at a predetermined voltage level, and an output terminal electrically coupled to said eighth terminal of said multiplexer circuit; e) wherein, in a first condition, said multiplexer circuit electrically couples its said first terminal to its said fifth terminal and to its said seventh terminal, and further electrically couples its said second terminal to its said sixth terminal and to its said eighth terminal, and wherein, in a second condition, said multiplexer circuit electrically couples its said third terminal to its said fifth terminal and to its said seventh terminal, and further electrically couples its said fourth terminal to its said sixth terminal and to its said eighth terminal.