Read Channel With AGC And Equalization
Original Publication Date: 1979-Feb-01
Included in the Prior Art Database: 2005-Feb-19
A read channel to provide an analog signal output of essentially similar amplitude irrespective of the data frequency from a transducer can be accomplished using the circuits shown in the figure. The pulses from the transducer are directed to a preamplifier 1 for initial amplification. The signals from the preamplifier are then directed to an equalizing filter 2 to remove any amplitude variations due to the dynamic variations in the input signals. The signal output from the equalizer 2 is directed to a variable gain amplifier 3 that provides an automatic gain control (AGC) via a gain control signal directed to the variable gain amplifier 3. The output of the variable gain amplifier is directed to a utilization circuit and to a gain control loop which comprises a gated peak detector 4, a holding circuit 5.