A 0.5V 18.6nW Bandgap Voltage Reference with A Low-Leakage Sample / Hold Circuit

This paper proposes a Low-Leakage sampling/holding (S/H) circuit-based Bandgap reference (BGR) with ultra-low power and low supply voltage. Power consumption is reduced through periodic sampling. A $2 \times$ charge pump (CP) is used to supply the BJT, which relaxes the supply voltage to 0.45 V. An automatic tuning circuit is implemented to maintain the accuracy and temperature coefficient (TC) across varying temperatures. The proposed design is fabricated in a 55 nm CMOS process and the measurement results show that the proposed BGR consumes only 18.6 nW at $27^{\circ} \mathrm{C}$, achieving a TC of $25 \mathrm{ppm} /{ }^{\circ} \mathrm{C}$ over a temperature range of $-40^{\circ} \mathrm{C}$ to $125^{\circ} \mathrm{C}$ at 0.45 V. The line regulation is $0.19 \mathrm{~V} / \%$ from 0.45 V to 1 V.