The CIC Filter
CIC filters were invented by Eugene B. Hogenauer, and are a class of FIR filters used in multi-rate processing. The CIC filter finds applications in interpolation and decimation. Unlike most FIR filters, it has a decimator or interpolator built into the architecture. The figure at the right shows the Hogenauer architecture for a CIC Interpolator.
The system function for the composite CIC filter referenced to the high sampling rate, fs is:
Where:
- R = decimation or interpolation ratio
- M = number of samples per stage (usually 1 but sometimes 2)
- N = number of stages in filter
Characteristics of CIC Filters
- Linear phase response;
- Utilize only delay and addition and subtraction; that is, it requires no multiplication operations;
Read more about this topic: Cascaded Integrator-comb Filter