A 150-nA 13.4-ppm/deg. C switched-capacitor CMOS sub-bandgap voltage reference

A nanopower switched-capacitor CMOS sub-bandgap voltage reference has been implemented using a Chartered 0.35-μm 3.3-V/5-V dual gate mixed-signal CMOS process. The proposed circuit generates a precise sub-bandgap voltage of 1 V. The temperature coefficient of the output voltage is 13.4 ppm/deg. C with the temperature varying from -20 to 80 deg. C. The proposed circuit operates properly with the supply voltage down to 1.3 V, and consumes 150 nA at room temperature. The line regulation is 0.27%/V. The power supply rejection ratio at 100 Hz and 1 MHz is -39 dB and -51 dB, respectively. The chip area is 0.2 mm2. (semiconductor integrated circuits)