Class AB emitter follower buffers
US6154063A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 26, 1999 |
| Grant date | Nov 28, 2000 |
| Priority date | — |
| Expiry date | Apr 26, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F3/50
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Buffers having an output pull-up transistor controlled by the input signal, an output pull-down transistor and a pull-down transistor control circuit. A current source provides a current that is divided between the pull-up transistor and the pull-down transistor control circuit to maintain the desired output voltage. A boost capacitor is coupled between the output and the pull-down transistor control circuit to provide good dynamic response to the circuit even in the presence of substantial capacitive loads on the output. In addition a second capacitor is coupled between the pull-down transistor control circuit and a fixed voltage to provide a low frequency pole internal to the circuit. The connection of the boost capacitor to the pull-down transistor control circuit and the connection of the second capacitor to the pull-down transistor control circuit are separated by a substantial resistance, allowing the effect of each capacitor to be substantially independent of each other. Exemplary circuits are disclosed incorporating these and other features.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.