一种BiCMOS带隙基准电压源的设计

Design of a bandgap voltage reference of BiCMOS

设计了低温度系数、高电源抑制比BiCMOS带隙基准电压发生器电路．综合了带隙电压的双极型带隙基准电路和与电源电压无关的电流镜的优点．电流镜用作运放，它的输出作为驱动的同时还作为带隙基准电路的偏置电路．使用0．6μm双层多晶硅n-well BiCMOS工艺模型，利用Spectre工具对其仿真。结果显示当温度和电源电压变化范围分别为-45～85℃和4．5～5．5V时，输出基准电压变化1mV和0．6mV；温度系数为16×10^-5／℃；低频电源抑制比达到75dB．电路在5V电源电压下工作电流小于25μA．该电路适用于对精度要求高、温度系数低的锂离子电池充电器电路．

A bandgap voltage reference （BGR） of BiCMOS with high PSRR and low power dissipation was designed. The bipolar bandgap voltage reference circuit and an OPAMP, supply-independent biasing, were used in the design. The output of the OPAMP, as a bias of the bipolar circuit, was used to drive the next stage. A mixture signal model of 0.6μm-double poly-n-well BiCMOS was simulated by Spectre tool. The simulation results showed that the output voltage varies within 1 mV and 0.6 mV with temperature range of -45℃ to 85℃ and the supply voltage from 4.5 V to 5.5 V respectively with a temperature coefficient of 16 × 10^-6/℃. The low frequency of PSRR is higher than 75 dB and the maximum supply current is 25μA with the 5 V supply. This circuit is adapted to integrated linear chargers with high precision and stability and low temperature coefficient for single cell Lithium-ion batteries.