Digital autozero circuit operable in a plurality of modes with separate storage for offset corrections for each mode
US5053770A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 18, 1990 |
| Grant date | Oct 1, 1991 |
| Priority date | — |
| Expiry date | May 18, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/183
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An autozero compensation system for autozeroing the output of a data conversion circuit comprising a floating point amplifier and an analog-to-digital converter. The autozero compensation system comprises a source for generating a desired offset voltage, a plurality of digital counters, one for each gain setting of the amplifier, for storing values which are functions of the offset voltages for the gain settings, and a comparator for comparing the output of the A/D converter with the desired offset. Periodically, each of the counters in the autozero circuit is updated for each gain setting by setting the analog input of the amplifier to system ground and the gain of the amplifier set to each of the gain settings, so that the output of the comparator is used to update each of the counters. The outputs of the counters are each converted to analog form by a D/A converter and used to provide the offset correction voltage to the floating point amplifier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.