A Sub-300-pW Voltage Reference with -227-dB PSR Using ΔvGS and Multi-Loop Regulation

In this work, we present a single-branch voltage reference with outstanding immunity to supply voltage variations. This is achieved by combining a Δ VGS-based core, responsible for temperature compensation, with a multi-loop regulation approach. The latter technique has been adapted to allow seamless operation within a large supply voltage range, down to 0.4 V, while maximum supply immunity is achieved at 0.8 V. Electrical simulations of a 0.18-μ m CMOS design demonstrate power-supply rejection as low as -226.6 dB at dc under 0.8-V supply voltage. Power consumption is below 300 pW, and the temperature coefficient is around 20 ppm/ °C between -20 and 80 °C. Performance is robust against random process variations, emulated through Monte Carlo statistical simulations. These findings indicate strong suitability of the proposed circuit for inclusion in low-power microchips subject to low and widely-fluctuating supply voltages.