Offset corrected amplifier
US3988689A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 7, 1975 |
| Grant date | Oct 26, 1976 |
| Priority date | — |
| Expiry date | Feb 7, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F1/303
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A circuit for cancelling the offset voltage of a signal amplifier includes a second amplifier and a third amplifier connected to the outputs of the signal amplifier and the second amplifier. A capacitor is connected between the inputs of the second amplifier for storing the offset voltages of the amplifiers thereon. A switch connects the output of the third amplifier to the capacitor and a switch connects the inputs of the signal amplifier together during offset correction. When the offset voltages are stored on the capacitor, the switches open to permit signal amplification and cancellation of the offset voltages. In a second embodiment, a second capacitor stores the instantaneous amplitude of the signal being amplified and supplies it to an input of the second amplifier such that a discontinuity will not appear in the circuit output during offset correction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.