Automatic gain control circuit
US9143110B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 2012 |
| Grant date | Sep 22, 2015 |
| Priority date | — |
| Expiry date | Jul 31, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03G3/3084
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An automatic gain control circuit (5a) includes a peak detector circuit (10) that detects the peak voltage of the output signal from a variable gain amplifier (3), an average value detection and output amplitude setting circuit (11) that detects the average voltage of the output signals from the variable gain amplifier (3) and adds a voltage ½ the desired output amplitude of the variable gain amplifier (3) to the average voltage, and a high gain amplifier (12) that amplifies the difference between the output voltage of the peak detector circuit (10) and the output voltage of the average value detection and output amplitude setting circuit (11) and controls the gain of the variable gain amplifier (3) using the amplification result as a gain control signal. The peak detector circuit (10) includes transistors (Q1, Q2, Q3), a current source (I1), and a filter circuit. The filter circuit includes a series connection of a resistor (Ra) and a capacitor (C1).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.