A novel pulse equalizer for hard disk systems is discussed. Opposed to classical realizations, it is full CMOS while operating at 50 MHz cutoff frequency. It is explained how the equalizer can be extended with a selective boost of 13 dB around the cutoff frequency for pulse slimming. The equalizer is a gm-C seventh-order, 0.05/spl deg/ equiripple-on-the-phase low-pass filter. It is made out of biquads with matched integrating nodes. The inaccuracies are compensated with a novel tuning system. This guarantees a ripple on the group delay of 2%. The results are confirmed on 0.7-/spl mu/m CMOS silicon.