Optimized Scheme for Power-of-Two Coefficient Approximation for Low Power Decimation Filters in
Ahmed Shahein, Markus M. Becker, Niklas Lotze, Maurits Ortmanns, Yiannos Manoli · 2008
A novel method for approximating filter coefficients to signed-power-of-two terms is proposed yielding a significant reduction in complexity and power consumption. A Matlab toolbox named MSD-Toolbox (Multi-Stage Decimation) was developed to design and optimize multi-stage decimation filters. The proposed design methodology was used to design an example dec- imation filter, which was synthesized in 0.13µm CMOS technology. The power consumption of the synthesized structure was analyzed. A reduction in power consump- tion of about 20% has been achieved for a 3-bit, second order lowpass sigma delta ADC decimation filter stage when compared with the conventional structure. For the well known quadratic polynomial objective function of FIR filters a novel subject constraint and limited signed-power-of-two space has been introduced.