Fully-integrated transimpedance amplifier for photoplethysmographic signal processing with two-stage Miller capacitance multiplier

A two-stage Miller capacitance multiplier for compensation is proposed to implement an ultra-low frequency fully-integrated transimpedance amplifier (TIA). With the proposed multiplier, the TIA achieves a passband gain of 89 dB??, a DC current rejection ranging from 0.5 to 85 ??A, and a -3 dB highpass cutoff frequency of 0.5 to 9.5 Hz. This corresponds to an improvement of six times in DC current rejection range compared with previous techniques.