Title: Design of a Low Temperature Drift Bandgap Reference Circuit with Second-order Curvature Compensation
Abstract: In order to improve the accuracy and stability of bandgap reference output voltage, a bandgap reference circuit with high power supply rejection ratio and low temperature drift is designed based on 0.18um BCD technology. Based on the traditional bandgap voltage reference structure, this paper designs a current mirror cascade and a prereference circuit to supply power to the bandgap reference, and achieves a high power rejection ratio. At the same time, a PTAT<sup>2</sup> current generation circuit is designed to realize the second-order temperature compensation of the reference output voltage. The simulation results show that the power supply voltage is 5V, PSRR is - 80dB, the temperature changes from - 55°C to 125°C, and the reference voltage temperature coefficient is 4.27ppm /°C. The circuit is simple in structure and easy to integrate. It can be widely used in bandgap reference circuit design.