Patent · US Expired

Clamping circuit for operational amplifiers

US7253687B2 · kind B2 · utility

1Cited by
1References
19Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 14, 2005
Grant dateAug 7, 2007
Priority date
Expiry dateDec 2, 2025

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03F2203/45636
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A differential input operational amplifier has a voltage clamp differential transistor pair coupled to an input differential transistor pair of the operational amplifier. The voltage clamp differential transistor pair limits the output voltage of the operational amplifier by taking over control of the operational amplifier circuits from the input differential transistor pair as the output voltage approaches a clamp voltage value. A reference voltage may be used to set the output voltage at which the input differential transistor pair will be clamped by the voltage clamp differential transistor pair. Below the clamp voltage, operation of the input differential transistor pair will not be affected. At the clamp voltage the input differential transistor pair will no longer control the output of the differential amplifier, rather the voltage clamp differential transistor pair will control the maximum voltage output of the differential amplifier. Both positive and negative limiting of the operational amplifier output voltage may be accomplished.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.