Gain control system and calibration method thereof
AssigneeMediatek Inc.
InventorsChia-Hua Chou, Tse-Hsiang Hsu
Life of this patent
Estimating the term…
Abstract
A gain control system for compact disc laser reader is provided, comprising two AGCs, comparator and a calibration unit. The first AGC receives a calibration signal to generate a first output signal with a first gain. The second AGC receives the calibration signal to generate a second output signal with a second gain. The comparator is coupled to the first and second AGCs, comparing the first output signal and the second output signal to generate a differential signal. The calibration unit, coupled to the comparator, adjusts the first control voltage or the second control voltage based on the differential signal, such that the amplitudes of the first output signal and the second output signal are compensated identically.
Claims10
A gain control system for a compact disc laser reader, comprising:
- a first AGC, receiving a calibration signal to generate a first output signal with a first gain, wherein the first gain is determined by a first control voltage;
- a second AGC, receiving the calibration signal to generate a second output signal with a second gain, wherein the second gain is determined by a second control voltage;
- a comparator, coupled to the first and second AGC, comparing the first output signal and the second output signal to generate a differential signal;
- and
- a calibration unit, coupled to the comparator, adjusting the first control voltage or the second control voltage based on the differential signal, such that the amplitudes of the first output signal and the second output signal are compensated identical.
A gain control system comprising:
- a first AGC, receiving a calibration signal to generate a first output voltage with a first gain, wherein the first gain is determined by a first control voltage;
- a second AGC, receiving the calibration signal to generate a second output voltage with a second gain, wherein the second gain is determined by a second control voltage;
- a comparator, coupled to the first and second AGCs, comparing the first and second output voltages to generate a differential signal;
- an third AGC, coupled to the comparator, amplifying the differential signal based on a predetermined voltage, and detecting the amplitude of the differential signal to generate a feedback signal;
- and
- a calibration unit, coupled to the third AGC, adjusting the first and second control voltages based on the feedback signal, such that the amplitudes of the first and second output voltages are equalized.
A calibration method for a gain control system comprising a first and a second AGC, comprising:
- generating a first and a second control voltages to the first and second AGCs;
- amplifying a calibration signal by the first AGC to generate a first output voltage by reference of the first control voltage;
- amplifying the calibration signal by the second AGC to generate a second output voltage by reference of the second control voltage;
- comparing the first and second output voltages to generate a differential signal;
- and
- adjusting the first control voltage or second control voltage based on the differential signal, such that the amplitudes of the first output voltage and second output voltage are equalized.
Dependencies are inferred from the claim text.