Low-Temperature Drift Bandgap Reference Based on Exponential Compensation Design

Abstract In analogue and mixed-signal systems, a stable and accurate reference voltage source is essential to ensure system performance. In this paper, a high-precision bandgap reference (BGR) with a high power supply ripple rejection ratio (PSRR) and lowtemperature drift is proposed, which mainly consists of a core circuit, an exponential temperature compensation circuit, a PSRR enhancement circuit and a start-up circuit. The PSRR is improved by using a PSRR enhancement circuit and a low-pass filter. An exponential compensation circuit is used to reduce the temperature drift coefficient of the bandgap reference. Based on a 0.18 μm BCD process for design and simulation, the output reference voltage is 1.203 V with a temperature drift coefficient of 2.635 ppm/°C over the temperature range of −40°C to 125°C. The PSRR is −144.4 dB at a frequency of 10 Hz, and −43.8 dB at a frequency of 1 MHz, and the layout area is 316 μm × 156 μm.