A HIGH-SPEED, LOW-POWER PRML READ CHANNEL DEVICE

A complete read channel device using PR-IV signalling and maximum like lihood detection is described. Descriptions, simulated performance and measured results of the digital adaptive feedback loops (AGC, FIR tap weights, DFE tap weights, frequency and phase) in the read channel ar e presented. Analog FIR filter and flash A/D converter performance is presented. The weighted averaging servo demodulation technique used in the device is described and compared to integration. This monolithic CMOS device consumes less than 0.75 W when reading at 85 Mbps, and occ upies a step-and-repeat area of 24.6 mm2.