A low-temperature drift voltage reference with high-order temperature compensation

A low-temperature drifting bandgap reference circuit with high-order temperature compensation was designed to solve the problem of poor temperature characteristics of traditional Brokaw bandgap reference. In this design, a high-order temperature compensation was formed by adding a base current of the transistor, which reduces the temperature coefficient of the bandgap reference. The loop negative feedback method was used to replace the clamping of the op amp to the circuit, which simplifies the circuit and reduces the impact of operation amplifier misalignment. The design of the low-temperature drifting bandgap reference was completed based on the Dongbu 0.18 um BCD process, and the circuit was simulated by Candence spectre, and the simulation results showed that the temperature coefficient of the bandgap reference was 1.918×10-6/°C in the temperature range of -55°C~125°C. In the low frequency range of 0~10kHz, the power supply rejection ratio reaches 87.3dB. At 1Mhz, the power supply rejection ratio reaches 62.2dB.