Implementation of a low-power accumulator for filter applications

A highly power-optimised accumulator is developed which can be used for integration circuits in comb filters. Comb filters have operands of high bitwidth and the accumulators used need huge sign extension at the input. The power consumed by the integration circuits is mainly due to the switching of the input data. By designing the accumulators without sign extension at the input, a power reduction of up to 60% is obtained (depending on the input data pattern). Implementations of this optimised accumulator in a 1-channel, 2- and 12-bit input, 25-bit output, 10 MHz comb filter is illustrated in this paper.