Design of a Bandgap Reference Circuit with High PSR and Low Quiescent Current

This paper presents a bandgap reference circuit with high power-supply rejection (PSR) and low quiescent current, specifically designed for power management integrated circuits. The proposed architecture enhances the Brokaw-type bandgap reference by incorporating a pre-regulator circuit, which generates a stable voltage to power the core bandgap reference circuit. Additionally, a low-distortion, high-gain folded-cascode operational amplifier is employed to further improve the power supply rejection capability. The bias circuit utilizes a cascode current mirror operating in the subthreshold region, effectively reducing the quiescent current.The circuit was fabricated using a $0.18 \mu \mathrm{~m}$ BCD process and implemented in a dual-channel load switch chip. Experimental results demonstrate that the proposed bandgap reference circuit achieves high power-supply rejection ratios (PSRR) of $97 \mathrm{~dB}, 100 \mathrm{~dB}$, and 101 dB at low frequencies under $2.4 \mathrm{~V}, 3.3 \mathrm{~V}$, and 5 V supply voltages, respectively. Furthermore, the circuit exhibits a low temperature coefficient of $7.6 \mathrm{ppm} /{ }^{\circ} \mathrm{C}$ over the temperature range of $-40^{\circ} \mathrm{C}$ to $135^{\circ} \mathrm{C}$, with a total current consumption of only $10.78 \mu \mathrm{~A}$.