Method and apparatus for exponential gain variations with a linearly varying input code
US6628164B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 2002 |
| Grant date | Sep 30, 2003 |
| Priority date | — |
| Expiry date | Apr 16, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03G1/0088
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A programmable gain amplifier using metal-oxide-semiconductor (MOS) devices to approximate exponential gain characteristic with linear control signals is disclosed. According to one embodiment, the programmable gain amplifier (300a-300b) may include a capacitive switching circuit (304a-304b), a capacitive switching circuit (306a-306b), and an operational amplifier (302a-302b). Capacitive switching circuits (304a-304b and 306a-306b) may receive an analog input voltage through sample switches (308a-308b and 310a-310b). Capacitive switching circuit (304a-304b) receives an output from operational amplifier (302a-302b) through feedback switch (312a-312b). The programmable gain amplifier (300a-300b) may include a few additional unit capacitors which can allow larger gain ranges or more steps for a given range without a large increase in chip size.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.