Design of low-power low-voltage switched-opamp based bandpass filter for microstimulator

A low-power low-voltage switched-capacitor bandpass filter with cross-coupling switched-opamp is presented. The proposed switched-opamp circuit is more stable for low-voltage operation and has the enhanced DC gain of 79 dB and the unity-gain bandwidth of 41 MHz. Using a 0.25 /spl mu/m CMOS technology with 1-V supply voltage, the proposed sixth-order filter possesses frequency response centered at 1.118 kHz with a Q-value of 0.235 and power saving in the biquad operation. Meanwhile, it is applied to microstimulators and the total power consumption is 402 /spl mu/W.