Dual mode charge pump for automatic gain control circuits
US5416437A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 26, 1994 |
| Grant date | May 16, 1995 |
| Priority date | — |
| Expiry date | Sep 26, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03G1/0088
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A dual mode charge pump for an AGC circuit is described. The charge pump of the present invention provides normal and accelerated rates of charge and discharge of a capacitor used to control the gain of an AGC amplifier. Current sources for providing accelerated charge and discharge rates are deselected when not needed. Since these current sources consume substantial amounts of power, deselecting them increases efficiency and reduces unnecessary power consumption. The current sources may be deselected internally or may be switched off by a switches in series with the current sources. The present invention also may be used to provide a self-timing function. The self-timing function allows the AGC to acquire the correct gain in an optimum time after initiation by an external control signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.