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Self-Clocking Multiple-Threshold Analog Comparator Circuit

IP.com Disclosure Number: IPCOM000034358D
Original Publication Date: 1989-Feb-01
Included in the Prior Art Database: 2005-Jan-27
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Anderson, PM: AUTHOR [+2]

Abstract

The circuit accomplishes AC signal measurement with self-clocking, high accuracy, no trimming, good high-frequency response, and uses a set of precision latching comparators to compare an AC analog signal to several thresholds simultaneously. It also uses a set of latches and clock generation circuitry to be self-clocking, or clocked by the fundamental frequency of the input signal, providing automatic synchronization and frequency independence. The desired results are achieved using precision latching comparators, along with are a set of latches and clock generation circuitry. The circuit is shown in the figure. As shown, the AC Input Signal goes to the inputs of a set of high-speed Latching Comparators 1, 2, etc. The reference inputs Thresh 1, 2, etc., are the desired threshold voltages.

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Self-Clocking Multiple-Threshold Analog Comparator Circuit

The circuit accomplishes AC signal measurement with self-clocking, high accuracy, no trimming, good high-frequency response, and uses a set of precision latching comparators to compare an AC analog signal to several thresholds simultaneously. It also uses a set of latches and clock generation circuitry to be self-clocking, or clocked by the fundamental frequency of the input signal, providing automatic synchronization and frequency independence. The desired results are achieved using precision latching comparators, along with are a set of latches and clock generation circuitry. The circuit is shown in the figure. As shown, the AC Input Signal goes to the inputs of a set of high-speed Latching Comparators 1, 2, etc. The reference inputs Thresh 1, 2, etc., are the desired threshold voltages. The Latching Comparators start out reset and latch when a cycle of the Input Signal goes higher than the appropriate threshold. The Latching Comparator Ck circuit also starts out reset. Its reference is Ck Thresh, a reference voltage lower than any of the other Thresholds. It should be far enough above ground potential to keep the circuitry from triggering on noise, but must be below the level of the other Thresholds. The Latching Comparator Ck circuit is triggered as the Input Signal goes lower than the Ck Thresh (toward ground potential). Two Ck Pulses are then generated. The first, Ck Pulse 1, clocks the data from th...