Design of high-accuracy band-gap voltage reference

In view of the traditional CMOS bandgap voltage reference source circuit power voltage is higher and reference voltage output range is limited.By increasing the starting circuit, and using the cascode configuration of PTAT current generating circuit,designed a high precision, low temperature drift, having a stable voltage output characteristic of the bandgap voltage source independent of the power supply.Based on 0.5μm high voltage BiCMOS process for circuit simulation, the results show that the band-gap reference circuit in the range of-40 ℃ ～ 85 ℃ temperature coefficient is 7ppm / ℃, at room temperature,the band-gap reference voltage is1.215V.