Patent ID: 6577196
Filing Date: 2003-06-10
Classification: H03G

Abstract:
Automatic gain control circuit for setting the gain of a signal amplifier comprising:a peak value detector for measuring signal amplitudes of the analogue signal which is amplified by the signal amplifier and for outputting a sequence of signal amplitude values; a comparator circuit which compares the measured signal amplitudes of said sequence of signal amplitude values with an upper amplitude threshold value and a lower amplitude threshold value and generates a range display data group composed of a sequence of digital range display data items which in each case indicate whether the measured signal amplitudes lie below the lower threshold value, between the two threshold values or above the upper threshold value; and a digital control circuit which evaluates a distribution of said digital range display data items of said range display data group statistically and incrementally changes the gain of the signal amplifier until the portion of the digital range display data items of a range display data group which indicate that the measured signal amplitudes between the amplitudes threshold values lie in a lock-in amplitude range exceeds a first predefined minimum portion threshold value.