A 0.052 mm2, <0.4% THD, Sinusoidal Current Generator for Bio-Impedance Measurement Using a Recursive Digital Oscillator and Current-Domain FIR Filter

摘要

This brief presents a low-power, low-area and low total harmonic distortion (THD) sinusoidal current stimulator circuit for bio-impedance measurement. Proposed current generator includes recursive digital oscillator for sine wave generation and delta-sigma modulated 1 bit current source with embedded finite impulse response filter for high resolution digital-to-current conversion. The proposed circuit implemented in 0.18-mu m CMOS process occupies 0.052 mm(2), and consumes 55.6 mu W for 20 kHz, 40 mu A(p-p), 0.17% THD sine current generation.