Maxim MAX11068 12路智能数据采集方案

Maxim 公司的MAX11068 是可编程高度集成高压12路电池监视智能数据采集接口电路，它的模拟前端包括12路电压测量数据采集系统和高压开关组输入，测量范围0-5V，满规格保证精度从0.5V 到 4.7V，测量精度±0.25%，失调电压≤ 5mV。MAX11068集成了6V-70V输入的线性稳压器，以及25ppm/NC, 2.5V精密基准电压源。主要用在汽车系统，混合电力汽车电池组，电动汽车，大功率电池备分系统以及SuperCap备分系统和动力工具。本文介绍了MAX11068主要特性，功能方框图，模拟前端（AFE）方框图，多种应用电路以及MAX11068 评估套件主要特性，详细电路图和材料清单（BOM）。
The MAX11068 is a programmable, highly integrated, high-voltage, 12-channel, battery-monitoring smart data-acquisition interface. It is optimized for use with batter­ies used in automotive systems, hybrid electric battery packs, electric cars, and any system that stacks long series strings of secondary metal batteries. This highly integrated battery sensor incorporates a simple state machine and a high-speed I2C bus for SMBusK-laddered serial communication.
The MAX11068 analog front-end combines a 12-channel voltage measurement data-acquisition system with a high-voltage switch bank input. All measurements are done differentially across each cell. The full-scale measurement range is from 0 to 5.0V, with full stated accuracy guaran­teed from 0.5V to 4.7V. The input mux/switch bank allows for differential measurement of each cell in a series stack. A high-speed, 12-bit successive approximation (SAR) A/D converter is used to digitize the cell voltages. All 12 cells can be measured in less than 107Fs. The MAX11068 uses a two-scan approach for collecting cell measurements and correcting them for errors. The first phase of the scan is the acquisition phase where the voltages of all 12 cells are acquired. The second phase is the error-cancellation phase where the ADC input is chopped to remove errors. This two-phase approach yields excellent accuracy over temperature and in the face of extreme noise in the sys­tem. The MAX11068 incorporates an in...