Automatic gain control circuit and automatic gain control method

摘要

An automatic gain control method includes receiving a sequence of multiple digital data, and calculating a plurality of signal values corresponding to the respective voltage values of the digital data, such as multiple peak-to-peak voltage values or power values, so as to optimize a gain according to variations in the output values. The gain optimization includes updating a reference value according to the signal values. If the reference value is less than a minimum threshold, the gain is increased to cause the reference value to reach the minimum threshold. The gain optimization also includes analyzing a clipping rate according to the signal values. If the clipping rate is equal to zero, then the gain is adjusted up. If the clipping rate is greater than zero, then the gain is adjusted down, such that the clipping rate is decreased to approach to zero.

主权项

1. An automatic gain control circuit, used to adjust a gain of an amplifier, comprising:
a reference value generator, configured to compare a plurality of signal values obtained from a plurality of digital data with a reference value, so as to update the reference value according to a result of the comparison; a clipping rate generator, configured to calculate a number of signal values substantially equal to at least one saturation value in a plurality of signal values obtained from the plurality of digital data, so as to generate a clipping rate according to the number; and an automatic target value controller, to generate a target value signal for adjusting the gain of the amplifier according to the reference value and the clipping rate.