Rail-to-rail class AB output stage for operational amplifier with wide supply range
US6545538B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 3, 2000 |
| Grant date | Apr 8, 2003 |
| Priority date | — |
| Expiry date | Oct 3, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45318
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A rail-to-rail class AB output stage includes a P-channel pull-up transistor (4) having a source coupled to a first supply rail voltage (V+), a gate coupled to a first input conductor (2) of the output stage, and a drain coupled to an output terminal (6) of the output stage. An N-channel pull-down transistor (5) includes a source coupled to a second supply rail voltage (GROUND), a gate coupled to a second input conductor (3) of the output stage, and a drain coupled to the output terminal (6). A P-channel first bias transistor (20) includes a source coupled to the first input conductor (2) and a drain coupled to the second input terminal (3). A first bias circuit coupled between the first and second supply rail voltages produces a first bias voltage (21) on a gate of the first bias transistor (20). A P-channel second bias transistor (10) includes a source coupled to be first input conductor (2). An N-channel third bias transistor (11) includes a source coupled to the second input terminal (3) and a drain connected to a drain of the second bias transistor (10) and to a non-inverting input of a servo amplifier (12) having an output coupled to a gate of the second bias transistor (10) …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.