用于电池管理系统的高压多路选择器

摘要

A high voltage multiplexer which is used to transmit and transform high common-mode voltage in battery management system (BMS) is proposed.The high voltage multiplexer consists of some high voltage switches and a level shift circuit.In the level shift circuit,two kinds of schemes implemented with resistance-voltage-divider and metal-layer finger capacitor are used to break through the barrier that normal capacitor cannot withstand high voltage.A calibration scheme used to calibrate the mismatch of capacitors and resistors and reference voltage deviation is proposed.A battery monitor IC with the proposed high voltage multiplexer is designed with a 0.25 μm 1-poly 4-metal 80 V BCD process.The post-layout-extracted simulation results of high voltage multiplexer indicate that the maximum error decreases to 1.9％ from 11.2％ with resistance-voltage-divider scheme and the maximum error reduces to 2.7％ from 8.7％ with metal-finger-capacitor scheme.The high voltage multiplexer can transmit and transform 0-70 V common voltage.%提出了一种用于在电池管理系统(BMS)中传输和转换高共模电压的多路复用器.该多路复用器由高压开关和电平移位电路组成.在电平移位电路中,引入电阻分压器和金属层叉指电容两种结构,解决了普通电容器不能承受高电压的问题.提出了一种用于校准电容、电阻失配和参考电压偏差的校准方案.基于0.25 μm 1P4M 80 V BCD工艺完成该高压多路选择器设计,并用于一款电池监控芯片中.高压多路选择器版图提取的后仿真结果表明:采用电阻分压器方法,最大误差从11.2％降低到1.9％;采用叉指电容方法,最大误差从8.7％降低到2.7％.该高压多路复用器可以传输和转换0-70 V共模电压.