Low-distortion high-efficiency amplifier
US6107884A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 27, 1998 |
| Grant date | Aug 22, 2000 |
| Priority date | — |
| Expiry date | Nov 27, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F1/3217
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The invention is an improvement to an amplifier configuration employing an amplification stage (e.g., an operational amplifier) biased via biasing terminals and a follower stage (e.g., an emitter-follower BJT pair), the follower stage being capable of producing the same voltage as the amplification stage but at a higher current. The improvement consists of feeding a fraction of the output voltage of the follower stage to the biasing terminals of the amplification stage. Specifically, the output of the follower stage is connected to the biasing terminals via a common bootstrap resistor and respective capacitors. The capacitors behave as a DC block and as an AC short-circuit. The biasing terminals are then connected to respective biasing resistors which could then be connected to respective supply voltage sources. In this way, the maximum permitted amplitude of the output voltage is increased, leading to less distortion and less frequent saturation of transistors in the amplification stage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.