A Low-Power High-PSRR CMOS Voltage Reference with Active-Feedback Frequency Compensation for IoT Applications

A low-power CMOS voltage reference with active-feedback frequency compensation is proposed for power-constrained IoT applications whereby power supply ripple rejection (PSRR) performance is critical for the survival of the devices. The proposed voltage reference consists of MOS transistors operating in the sub-threshold region to allow for low-voltage and low-power operations. An active-feedback frequency compensation technique has been used to make the loop stable and improve the PSRR with a very small compensation capacitor while allowing a relatively large output capacitor. The circuit is fabricated in a standard 0.18-mu m CMOS process. The measured power consumption is 22nW at 0.7V power supply. The measured temperature coefficient (TC) is 38ppm/degrees C in a range from -40 to +110 degrees C, and the line regulation is 200 mu V/V in a supply voltage range of 0.7 similar to 2V. The measured PSRR at 10 Hz, 1 kHz, and 100 kHz is -64dB, -56dB, and -52dB, respectively. The active chip area is 0.04mm(2).