An Improved Bandgap Reference with Curvature-Compensated and High Power Supply Rejection

Abstract

This paper presents a bandgap reference (BGR) with the characteristics of curvature-compensation and high power supply rejection ratio (PSRR). To achieve a better performance, the base current of BJT is injected to a small segment of resistor string to flatten the temperature variation, and a pre-regulator of the power supply is implemented to improve the PSRR. The circuits, designed in 0.18[Formula: see text][Formula: see text]m BCD technology, exhibit an average voltage of 1.212[Formula: see text]V with temperature coefficient of 2.0[Formula: see text]ppm/[Formula: see text] in the range from [Formula: see text] to 110[Formula: see text] at typical condition, and a power supply rejection ratio of [Formula: see text][Formula: see text]dB at low frequency. After 4-bit trimming, Monte Carlo simulation results show that the proposed design gets an accuracy of 0.29%, with a variation of [Formula: see text][Formula: see text]mV. The active design area is 160[Formula: see text][Formula: see text]m, and the power supply current is about 8.2[Formula: see text][Formula: see text]A.