Generic Droop Correction IIR Filter Design Algorithm

Cascaded Integrated Comb (CIC) or Multiplier-less Hogenauer structure for multi-rate signal processing has uncontrollable frequency response. State-of-Art (SOA) solution to achieve controllable frequency response is to cascade the Hogenauer filter with a droop-correction Finite Impulse Response (FIR) filter. Although FIR filters are linear phase and inherently stable, Infinite Impulse Response (IIR) filters provide excellent frequency response with the cost of less memory and hence less area and less current consumption, which have never been explored in the context of droop correction. This article introduces a novel algorithm which generates IIR structures to correct droop imposed by Hogenauer structures, which also can be used to save area and power with a better transition and stop-band response in comparison to the equivalent FIR filter. Furthermore, this algorithm can be assimilated as a part of existing algorithm design tool, like MATLAB or SciLab.