CIC ( Cascaded Integrator Comb) filters are a popular way to do decimation ( as one of a chain of filters). Usage is in delta – sigma ADC’s and similar circuits. A recent paper by Signal Processing Group Inc. describes the design process of such a filter. This paper is available on the Signal Processing Group Inc. website under the “Complementary” menu item.

There are at least three fundamental parameters we need to know when designing a modulator for a delta sigma ADC. These are: The ENOB or equivalent number of bits, the modulator order and the rank of the quantizer. These are the inputs to the modulator design algorithm. Signal Processing Group Inc., provides a calculator to evaluate what the SNR will be and the oversampling ratio. Please visit www.signalpro.biz/calc_delsig1.htm
to invoke the calculator.