DESIGN OF A CMOS BANDGAP REFERENCE WITH LOWTEMPERATURE COEFFICIENT AND HIGH POWER SUPPLY REJECTION PERFORMANCE

A high precision temperature compensated CMOS bandgap reference is presented. The proposed circuitemploys current-mode architecture that improves the temperature stability of the output reference voltageas well as the power supply rejection when compared to the conventional voltage-mode bandgap referenc.Using only first order compensation the new architecture can generate an output reference voltage of550mV with a peak-to-peak variation of 400μV over a wide temperature range from -25oC to +100oCwhich corresponds to a temperature coefficient of 5.8ppm/oC. The output reference voltage exhibits avariation of 2.4mV for supply voltage ranging from 1.6V to 2.0V at typical process corner. A differentialcascaded three-stage operational amplifier is included in the bandgap circuit to improve the power supplyrejection of the BGR. Simulation result shows that the power supply rejection ratio of the proposed circuitis 79dB from DC up to 1kHz of frequency. The proposed bandgap reference is implemented using UMC0.18μm CMOS process and it occupies an active layout area of 0.14mm2.