2. Challenge of High Performance Bandgap Reference Design in Nanoscale CMOS Technology

To design a high performance bandgap reference circuit in nanoscale CMOS technology becomes a great challenge. Many negative effects of nanoscale CMOS technology in high performance bandgap reference design are discussed in this chapter. A bandgap reference circuit design with both voltage output and current output is presented also. In this design, low threshold voltage MOSfet have been utilized in this design to ensure the circuit at suitable DC operation points under extreme low temperature. Operational transconductance amplifier (OTA) has been used to achieve high DC power supply rejection rate (PSRR). Two opposite temperature coefficient resistors have been connected in series to obtain a one-order temperature independent resistor which also achieves a weak curvature compensation effect for reference voltage’s generation. This bandgap reference is implemented in a 65 nm CMOS technology, occupies 0.75 × 0. 67 mm including bond pads, Measured results show that this circuit can operate at supply voltage from 1.1 to 1.3 V, and the temperature coefficient of voltage output is 30 ppm/°C with 60 dB PSRR (DC, 30°C), and the temperature coefficient of current output is 52 ppm/°C with 70 dB PSRR (DC, 30°C), among −55°C to 125°C without any trimming or calibration.