Low-Cost Digitally-Programmable CMOS Switched-Capacitor Biquad

The digital programmability of an SC biquad using quasi-passive algorithmic DACs leads to a significant reduction of the overall capacitor area needed for integration and therefore offers a more compact, cost-effective solution than binary-weighted C-arrays. This is demonstrated with a 1.2 μm CMOS prototype chip implementing an 8-bit programmable general purpose SC biquad that occupies a total active area of only 0.52 mm².