DC insensitive AGC circuit for optical PRML read channel
US6404829B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 29, 1999 |
| Grant date | Jun 11, 2002 |
| Priority date | — |
| Expiry date | Jun 29, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/10037
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
AGC Circuitry for an optical PRML read channel that is insensitive to low frequency disturbances of an RF input signal. The AGC Circuitry includes a VGA amplifier, a low pass filter, an ADC, a baseline Wander Correction Circuit, a digital gain control circuit, and a DAC. The VGA amplifier amplifies the RF input signal to produce a second RF signal. The low pass filter filters the second RF signal to produce a first analog signal. The ADC converts the first analog signal into a digital AGC output signal suitable for decoding. The baseline Wander Correction Circuit removes from the digital AGC output signal effects of low frequency disturbance of the RF input signal to produce a second digital signal. The digital gain control circuit controls the gain of the VGA amplifier by producing a digital gain control signal in response to the second digital signal. The DAC for converting the digital gain control signal into the analog gain control signal to be applied to the VGA amplifier, the analog gain control signal being substantially free from effects of low frequency disturbance of the RF input signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.