Design of second-order sub-bandgap mixed-mode voltage reference circuit for low voltage applications

This paper presents a second-order BiCMOS sub-bandgap voltage reference circuit for temperature range of -40 to 120 /spl deg/C. The sub-bandgap voltage is obtained through a new mixed-mode topology, which has the added advantage for obtaining high precision second-order temperature compensation. The circuit is designed in 0.5 /spl mu/m BiCMOS process. The reference voltage obtained is 475.2 mV at room temperature and has a temperature coefficient of less than 15 ppm//spl deg/C. The proposed circuit finds application in low voltage power management circuits.