Operational amplifier with digital offset calibration
US6262625A · kind A · utility
56Cited by
6References
26Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 29, 1999 |
| Grant date | Jul 17, 2001 |
| Priority date | — |
| Expiry date | Oct 29, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45726
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An operational amplifier includes transistors for providing a controlled current path. At least one of the transistors is in an isolated well in a substrate. Offset of the operational amplifier is corrected by applying a back gate bias voltage to at least one isolated well and changing impedance of the transistors. The proper back gate bias voltage and transistor impedance are determined by incrementally adjusting the back gate bias voltage and then incrementally adjusting the transistor impedance. Calibration values are stored in register memory. Such calibration may be performed by an auto offset calibration process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.