A high quality CMOS power regulator for a wireless endoscope

In this paper, we present the design of a low-power, high-power supply rejection ratio (PSRR) power regulator used in telemetry-powered bioimplantable microsystems in a 0.35μm standard CMOS process. The power regulator is comprised of a CMOS full-wave bridge rectifier, a wide-range and high PSRR voltage reference and a low drop out series voltage regulator. Simulation results show the proposed circuit provides 3V regulated DC output, exhibits load regulation factor of as low as 1% when delivering up to 30mA load current, and demonstrates line regulation factor of as low as 0.01%/V over 4.8V input amplitude variation.