Low power techniques and design tradeoffs in adaptive FIR filtering for PRML read channels

In this paper, we describe area and power reduction techniques for a low-latency adaptive finite-impulse response filter for magnetic recording read channel applications. Various techniques are used to reduce area and power dissipation while speed remains as the main performance criterion for the target application. A parallel transposed direct form architecture operates on real-time input data samples and employs a fast, low-area multiplier based on selection of radix-8 pre-multiplied coefficients in conjunction with one-hot encoded bus leading to a very compact layout and reduced power dissipation. Area, speed and power comparisons with other low-power implementation options are also shown. The proposed filter has been fabricated using a 0.18 μm L-effective CMOS technology and operates at 550 MSamples/s.