An op amp-less band-gap voltage reference with high PSRR and low voltage

With the trend of low-power, low-voltage in IC design, conventional band-gap voltage reference will not be the most suitable candidate anymore. In this paper, an op amp-less band-gap voltage reference is designed in 0.35um 5V/3.3V CMOS process. After the principle and stability of the voltage reference is introduced, the power supply noise rejection ratio (PSRR) and temperature coefficient in low voltage supply are analyzed too. The simulation results indicate that the temperature range is -40 to 125, the reference voltage is 1.166V - 1.171V and the PSRR is 104dB at 1KHz when the supply voltage range is 2.5V ± 10% So the proposed op amp-less band-gap reference has the features of high-PSRR, low-voltage and low temperature coefficient. It is very suitable to be applied in low voltage ADC and DAC.