Low noise auto-zero circuits for amplifiers
US8493139B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 17, 2011 |
| Grant date | Jul 23, 2013 |
| Priority date | — |
| Expiry date | Nov 29, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45726
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An amplifier may include a low noise auto-zero circuit with auto-zero capacitors and switch-controlled auxiliary capacitors that function as switched-capacitor low-pass filters. In an acquisition phase of the auto-zero operation, the inputs of an amplifier may be shorted to a common voltage, and a representation of the offset voltage may be acquired by the auto-zero capacitors. In a hold phase of the auto-zero operation, the auto-zero capacitors may be connected to the auxiliary capacitors, and the resulting voltages may be applied to the circuit such that the original offset voltage is cancelled. Moreover, the switched-capacitor filters may reduce the effective sampling noise while maintaining high acquisition bandwidth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.