A 1.1 ppm/°C Bandgap Reference Circuit with Piecewise Compensation in 0.18 um BCD Technology

The present study demonstrates the implementation of a bandgap reference in a 180 nm BCD process, showcasing exceptional performance in terms of low-temperature coefficient (TC) and high-power supply rejection ratio (PSRR). A piecewise compensation strategy is proposed to widen the temperature range. The current required for piecewise compensation is produced by two proportional to absolute temperature (PTAT) currents with different slopes, which are generated by the triode and the metal-oxide-semiconductor field-effect transistor (MOSFET) operating in the sub-threshold region, respectively. An enhancement circuit and cascode current mirrors are adopted to improve PSRR. The simulated result shows that the TC is 1.108 ppm/°C over a wide temperature range from −40°C to 125°C. The PSRR is as high as 99.5 dB at low frequencies with a 5 V power supply.