A bandgap reference in 65nm CMOS

Abstract

A bandgap reference circuit with voltage and current output is presented. Operational transconductance amplifier(OTA) have been used for a higher DC power supply rejection rate(PSRR) under small gate length of MOSfet. Both telescopic and folded OTA and low threshold voltage MOSfet have been used to ensure the circuit at suitable operation points under every PVT(process, source voltage and temperature) corner. Two opposite temperature coefficient resistors have been connected in series to obtain a temperature independent resistor for voltage reference's generation. This bandgap reference is implemented in a 65nm CMOS technology, occupies 0.75mm×0.67mm including bond pads, Measured results show that this circuit can operate at supply voltage from 1.1V to 1.3V, and the temperature coefficient of voltage output is 30.9ppm/oC with 61dB PSRR (DC, 25oC), and the temperature coefficient of current output is 51.6ppm/oC with 69dB PSRR (DC, 25 oC), among -55oC~125oC without any trimming or calibration.