Rail-to-rail input/output operational amplifier and method
US6356153B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 20, 2000 |
| Grant date | Mar 12, 2002 |
| Priority date | — |
| Expiry date | Nov 20, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45398
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A rail-to-rail differential amplifier includes first and second input terminals, and an output terminal and an input stage including differentially connected N-channel first and second input transistors, and differentially connected P-channel third and fourth input transistors. A P-channel first cascode transistor has a source coupled to a first supply voltage to the drain of the first input transistor. An N-channel cascode transistor has a source coupled by a second resistive element to a second supply voltage and to the drain of the third input transistor. A first gain boost amplifier has an output coupled to a gate of the first cascode transistor, a first input coupled to the source of the first cascode transistor and the drain of the first input transistor, and a second input coupled to a drain of the second input transistor and a bias control circuit. A second gain boost amplifier has an output coupled to a gate of the second cascode transistor, a first input coupled to the source of the second cascode transistor and to the drain of the third input transistor, and a second input coupled to a drain of the fourth input transistor and the bias control circuit. An output stage inc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.