Apparatus and method for transconductance stage with high current response to large signals
US7233171B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 2005 |
| Grant date | Jun 19, 2007 |
| Priority date | — |
| Expiry date | Aug 5, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45646
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A transconductance stage is provided. The transconductance stage includes a tail current source, a differential pair, and two current mirrors. The input to each of the current mirrors is connected to the drain of a separate one of the transistors in the differential pair. The two current mirrors each have two outputs so that one of the outputs can be used to determine whether the output current exceeds a threshold (e.g. nine-tenths of the tail current). If the source current exceeds the threshold, extra source current is switched in to the output so that output source current is increased. Similarly, if the sink current exceeds the threshold, extra sink current is switched in to the output so that the output sink current is increased. This way, the transconductance stage can supply large output currents in response to a large signal input but maintains low quiescent current for small input signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.