A power efficient programmable gain boosting current mirror for biomedical electronics

Abstract

In this paper, a power efficient gain boosting current mirror with fast stand-by recovery (4.5μs) and a maximum gain of 80dB is proposed in a 0.35μm CMOS process with 3V power supply. The gain is achieved from the aspect ratios in transistors and deployed closed loop amplifier. In active mode, it can deliver upto 1mA from 0.1μA input current with approximately 1.2μA in biasing circuits. It consumes only 0.8μW during stand-by mode. A digital calibration circuit is employed to overcome device mismatch and process variation. This generates accurate output currents within a range of ±8%, whereas without calibration, the variation of ±33% at output currents is observed. This technique can be used in biomedical devices, which seek high power efficiency.