High-Precision Bandgap Reference with Piecewise Compensation and No Operational Amplifier

This paper presents the design of a high-precision bandgap reference source with piecewise compensation and no operational amplifier. The circuit uses a current-mode bandgap reference without an operational amplifier as the first-stage compensation circuit. By adjusting the resistance values in the first-stage compensation circuit, the output curve of the bandgap reference is shifted from the mid-temperature region to the high-temperature region. After the shift, the curve only shows a larger slope in the low-temperature region. Negative temperature coefficient current is injected into the low-temperature region to raise the voltage and complete the compensation. Simulations were conducted using a 0.18µm CMOS process on the Cadence Virtuoso platform. The simulation results show that the compensated reference voltage exhibits a temperature drift of only 0.741 ppm/°C in the temperature range of -40°C to 125°C.