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Multiple-Input Over-Voltage, Under-Voltage Window Comparator for Computer Power Supplies

IP.com Disclosure Number: IPCOM000038899D
Original Publication Date: 1987-Mar-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Riggio, SR: AUTHOR

Abstract

A technique is described whereby a multiple-input window comparator circuit provides the computer power supply circuitry with the ability to simultaneously sense various supply voltage levels for an over- voltage or under-voltage condition. This circuitry compares the various voltage levels with specified limits, so as to provide protection for computer circuitry, should a power supply voltage vary over or under specified limits. The circuit is unique in that it can be used with any set of output voltage levels, eliminating the need to customize comparator circuitry for each voltage in question. This is accomplished through a unique multiple-input front end on each of the two comparators.

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Multiple-Input Over-Voltage, Under-Voltage Window Comparator for Computer Power Supplies

A technique is described whereby a multiple-input window comparator circuit provides the computer power supply circuitry with the ability to simultaneously sense various supply voltage levels for an over- voltage or under-voltage condition. This circuitry compares the various voltage levels with specified limits, so as to provide protection for computer circuitry, should a power supply voltage vary over or under specified limits. The circuit is unique in that it can be used with any set of output voltage levels, eliminating the need to customize comparator circuitry for each voltage in question. This is accomplished through a unique multiple-input front end on each of the two comparators. In prior art, over- voltage and under-voltage sensing circuitry required the use of two customized integrated comparator circuits for each output voltage of the power supply. The circuitry described herein provides sensing and monitoring of all the voltages with one set of comparators, thereby eliminating the need to customize multiple comparator sets for each output voltage. A single set of window comparators is used to simultaneously sense and compare all the output voltages in the power supply. Comparisons are made to high and low reference limits, so as to provide a trip point to signal control circuitry at the output of the comparator that an over- voltage or under-voltage condition has...