CMOS Widely Tunable Second-Order Gm-C Bandpass Filter for Multi-Sine Bioimpedance Analysis

A CMOS widely tunable second-order Gm-C bandpass filter (BPF), intended to be used in multi-sine bioimpedance applications, is presented. The incorporates a transconductor which the responses of two linearized voltage-to-current converters are subtracted. As result, effective transconductance can continuously adjusted over nearly three decades, allows corresponding programmability center frequency BPF. circuit was designed and fabricated 180 nm technology operate with 1.8 V supply, experimental characterization carried out eight samples silicon prototype. simulated cell tuned from 5.3 nA/V up 19.60 ?A/V. measured range varied, however, between 1.42 ?A/V 20.57 Similarly, BPF, simulations ranged 500 Hz 342 kHz, programmed prototypes 22.4 kHz 290 kHz. Monte Carlo corner were ascertain origin this deviation. Besides, extensive simulation standalone complete BPF provided.