动力电池检测芯片高压MUX电路设计

Design of High Voltage Multiplexer for Battery Monitoring Chip

设计了一个输入为8节串联电池单体的模拟高压MUX电路,可用于动力电池检测芯片电压采集前端.高压MUX电路的主体是互补DMOS器件及栅极驱动电路组成的高压开关阵列,消除了信号通路上由静态电流引入的误差.MUX电路输出与宽共模输入差分电压检测前端相连,避免使用电平移位电路,在减少功耗的同时,提高了电压检测精度.电路设计仿真结果表明,在0.5μm 60VBCD工艺下,MUX电路工作电流30μA,无校准情况下由MUX电路引入的误差小于0.2mV.

A design of high voltage （HV） analog multiplexer （MUX） circuit has been presented. MUX circuit has voltage inputs of eight series connected battery cells, which is suitable for battery monitoring chip voltage detecting front-end. The main part of HV MUX is several parallel connected HV switches. A HV switch is composed of complementary DMOS devices and gate drive circuit, and has eliminated the error in the signal path caused by quiescent current. The MUX circuit drives a wide common mode range differential voltage detecting circuit. Elimination of level shifter circuit causes reduction in power consumption, and greatly improves the detecting accuracy. HV MUX has been designed under 0. 5 μm 60 V BCD process. The simulation results show that the operating current of MUX circuit is 30 μA, and the error introduced by the HV MUX circuit without calibration is less than 0. 2 mV.