High efficiency power amplifier
US6236273A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 18, 1999 |
| Grant date | May 22, 2001 |
| Priority date | — |
| Expiry date | Nov 18, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F3/3079
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A monolithic integrated circuit amplifier has a gain stage and a buffer stage. The buffer stage includes an output stage and two separate voltage supplies, the second of which has a greater magnitude than the first. Switching circuitry is included that is connected to the output stage via a regulator bus. When an output demand voltage is less than a switch-over threshold, current to the output stage is provided substantially entirely from the first voltage supply; when the output demand voltage is greater than the switch-over threshold, current to the output stage is provided substantially entirely from the second voltage supply. Collector voltage at the output stage can be maintained greater than the emitter voltage by a predetermined, substantially constant amount. Voltage headroom circuitry is preferably also included for setting a voltage headroom, that is, the lowest voltage constantly available at the second current terminal of the output transistor relative to the first current terminal of the output transistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.