A power efficient multirate multistage Comb decimation filter for monobit Σ∆ A/D converters is presented. Polyphase decomposition in all stages with high decimation factor in the first stage, are used to reduce the frequency of the input signal. Several implementations have shown that proper choice of the decimation factor of the first stage can reduce power consumption by more than 30% The multistage architecture makes the total decimation factor easily programmable and suitabale for multi-standard applications.