A single chip HDD PRML channel

A PRML (Partial Response Maximum Likelihood) channel chip employing a mixed-signal 0.8 /spl mu/m BiCMOS process for hard disk drive (HDD) applications is described. This chip performs the complete write, read, and servo functions using only five external components with a data rate of up to 120 Mb/sec. Under normal operating conditions the power dissipation is less than 800 mW. The on-chip circuitry includes ADC, VGA, FIR filter, Viterbi decoder, two PLL's, etc.