Equalization circuits for magnetic recording channels.

摘要

@ An adaptive equalization circuit for magnetic recording channels which derives an error signal to change the equalizer compensation value from the timing of random signal data and provides continuous feedback compensation.

In the Figure data from read head (21a) is amplified by amplifier (22a) and partially equalized in fixed equalizer (23a). The signal is applied to summation circuit (49) which receives a variable correction input signal. The summed signal is applied to data pulser circuit (24a) which provides output pulses to detector circuit (26a) and variable frequency clock (25a) at times of positive or negative peaks in the . received signal. The correction signal is derived from an equalization filter circuit (48) controlled by the output of a variable gain amplifier (47), the gain of which is set by the voltage on line (65). This voltage is determined by circuitry (69) from the three input supplied thereto.