Design of wide-supply-voltage-range bandgap reference circuits for voltage regulators

Bandgap voltage is typically used as the reference voltage of voltage regulators, such as dc-dc converters. Two high-precision CMOS bandgap reference circuits, labeled as current-mode and voltage-mode bandgap circuits, are proposed. The voltage-mode bandgap circuit can work with the supply voltage ranging from 2.5 V to 5V, while the current-mode bandgap works from 1.8 V to 5V. Both of them were designed and fabricated by using the TSMC 0.35-μm CMOS 3.3V/5V mixed-signal 2P4M polycide process. The measured temperature coefficient of the voltage-mode bandgap is 8.6 ppm/°C when supplied by a 5-V voltage. The measured line regulation of the voltage-mode bandgap is 0.16%/V, while that of the current-mode one is 0.13%/V.