Efficient polyphase decomposition of comb decimation filters inΣ▵ analog-to-digital converters

摘要

A power efficient multirate multistage Comb decimation filter fornmono-bit and multi-bit Σ▵ A/D converters is presented.nPolyphase decomposition in all stages, with high decimation factor innthe first stage, is used to significantly reduce the sampling frequencynof the Comb filter. Several implementations indicate that proper choicenof the first stage decimation factor can considerably improve powernconsumption, area and maximum sampling frequency. In multibitnΣ▵ A/Ds, this optimum first stage decimation factor is anfunction of the input wordlength