Method for stabilizing the gain of a discrete-state automatic gain control circuit
US9654070B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 22, 2015 |
| Grant date | May 16, 2017 |
| Priority date | — |
| Expiry date | May 22, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45512
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An automatic gain controller comprises an amplifier including a variable gain. A resonant low-pass filter includes an input coupled to an output of the amplifier. The resonant low-pass filter is a second order low-pass filter. The second order low-pass filter includes a Sallen-Key topology. The Sallen-Key topology comprises a quality factor between 1.4 and 1.6. A threshold detection circuit includes an input coupled to an output of the second order low-pass filter to compare an output signal of the second order low-pass filter to a threshold and an output of the threshold detection circuit coupled to control the variable gain of the amplifier. A state machine is coupled between the output of the threshold detection circuit and the amplifier. The state machine is configured to transition based on a current state of the state machine. The resonant low-pass filter exhibits overshoot to trigger a hysteresis of the threshold detection circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.