A Second-Order Curvature-Compensated Band-Gap Voltage Reference

A second-order curvature-compensated bandgap voltage reference with adjustable output voltage is presented,which employs the different temperature coefficients between poly resistor and N-well resistor in the CMOS process.The circuit was simulated by Cadence tool with Chartered 0.35 μm CMOS model.The results show that the circuit can operate down to a 1.8V supply,the variation of the output voltage is only 3.8 mV.The temperature coefficient of the output voltage reference is 1.6 ppm/°C from-40 °C to 80 °C and the current is 24 μA at supply voltage of 2 V,and the power supply rejection ratio(PSRR) is-47 dB at low-frequency.The bandgap voltage reference meets the need of low temperature coefficient,high stability,low supply voltage and low power consumption.