原标题：TI bq76PL455A-Q1高可靠汽车电池监测和保护方案

　　TI公司的bq76pl455A-Q1是16路高可靠汽车电池监测和保护方案,集成了高速差分电容隔离通信接口,高性能14位ADC,用于温度和其它传感器的八路输入复接器,精密基准电压.本文介绍了bq76PL455A-Q1主要特性,框图,数字和模拟芯片部分功能框图,应用电路框图,以及bq76PL455EVM评估模块主要特性和电特性,电路图和材料清单.

　　The bq76PL455A-Q1 device is an integrated 16-cell battery monitoring and protection device, designed for high-reliability automotive applications. The integrated high-speed, differential, capacitor-isolated communications interface allows up to sixteen bq76PL455A-Q1 devices to communicate with a host via a single high-speed Universal Asynchronous Receiver/Transmitter (UART) interface.

　　The bq76PL455A-Q1 monitors and detects several different fault conditions, including: overvoltage, undervoltage, overtemperature, and communication faults. Six GPIO ports as well as eight analog AUX ADC inputs are included for additional monitoring and programmable functionality. A secondary thermal shutdown is included for further protection.

　　The bq76PL455A-Q1 has features that customers may find useful to help them meet functional safety standard requirements (for example, ISO26262).

　　bq76PL455A-Q1主要特性:

　　Monitors and Balances 6-to-16 Cells per Device

　　Highly Accurate Monitoring

　　High Performance 14-bit Analog-to-Digital Converter (ADC) With Internal Reference

　　All Cells Converted in 2.4 ms (Nominal)

　　Eight AUX Inputs for Temperature and Other Sensors with Input Voltage of 0 V to 5 V

　　Internal Precision Reference

　　Integrated Protector With Separate Vref for Overvoltage (OV) and Undervoltage (UV) Comparators and Programmable VCELL Set Points

　　Engineered for High System Robustness

　　Up to 1-Mb/s Stackable Isolated Differential- UART

　　Up to 16 ICs in Daisy-Chain With Twisted Pair

　　Passes Bulk Current Injection (BCI) Test

　　Designed for Robust Hot-Plug Performance

　　Passive Balancing with External n-FETs and Active Balancing with EMB1428Q/EMB1499Q

　　Can Help Customers Meet Functional Safety Standard Requirements (For Example, ISO26262)

　　Built-in Self-Tests to Validate Defined Internal Functions

　　Support for Open Wire Detection

　　AEC-Q100 Qualified With the Following Results:

　　Device Temperature Grade 2: –40℃ to 105℃ Ambient Operating Temperature Range

　　Device HBM ESD Classification Level 2

　　Device CDM ESD Classification Level C3

　　图1.bq76PL455A-Q1功能框图

　　图2.bq76PL455A-Q1数字芯片部分功能框图

　　图3.bq76PL455A-Q1模拟芯片部分功能框图

　　图4.bq76PL455A-Q1单元连接图

　　图5.bq76PL455A-Q1主器件应用框图

　　图6.bq76PL455A-Q1其它应用框图

　　bq76PL455EVM评估模块

　　Texas Instruments’ passive balancing bq76PL455A-Q1 provides monitoring and balancing for a stack ofup to 16 series-connected lithium-ion battery cells. The bq76PL455A-Q1 operates on stack voltages froma 16 V minimum to a 79.2 V maximum. In addition to 16 battery cell measurement channels, eight (8)additional analog channels are provided for temperature or auxiliary signal sensing, and six (6) additionaldigital channels are provided. As an option, configure the digital channels to generate faults when the levelchanges state; either high to low, or low to high. Please refer to the bq76PL455A-Q1 data sheet(SLUSC51) for specification of channel voltage measurement accuracy over the 0 to 65°C and –40°C to105°C operating temperature ranges. The passive cell balancing current is set by onboard resistors to 56mA for a cell at 4.2 V.

　　For battery stacks with more than 16 cells, stack up to 6 bq76PL455EVMs, in series, to support up to 96cells. Communication with stacked bq76PL455EVMs is via an isolated daisy chain differential bus capableof withstanding 500 V. A stack of multiple bq76PL455EVMs can be woken from power down using asingle wake command from the GUI. System Faults are monitored and indicated in the GUI by simulatedLED fault indicators.

　　Control a single EVM or multiple stacked bq76PL455EVMs using a PC-hosted GUI. Communicationbetween the PC and the lowest in a stack of bq76PL455EVMs is via an FTDI USB-to-TTL (5V) serialinterface cable. Communication between all other EVMs in the stack is via the isolated, daisy chaindifferential communication bus. The PC GUI allows configuration of the bq76PL455EVMs to monitor cellsand other analog data channels, control balancing, and monitor details of any faults.

　　The bq76PL455EVM demonstrates the performance of Texas Instrument’s new highly integrated bq76PL455A-Q1 16-cell, battery stack monitoring, passive balancing device. The bq76PL455AQ1provides a highly accurate, reliable, and robust solution for battery management, integrating all of thefollowing components:

　　• 14-bit Analog-to-Digital Converter (ADC)

　　• Precision voltage reference

　　• Precision, high-voltage Analog Front End (AFE)

　　• Universal asynchronous receiver/transceiver (UART) serial communication interface

　　• LDO voltage regulator

　　• Control logic for monitoring, balancing, and communication functions

　　bq76PL455EVM评估模块主要特性:

　　• 16-channel precision voltage cell monitoring and passive balancing

　　• 8-channel temperature or auxiliary signal monitoring

　　• 6-channel digital signal monitoring, with optional fault monitoring

　　• Isolated serial communications

　　• Stackable, supporting up to 96 cells

　　bq76PL455EVM评估模块电特性:

　　• Operating voltage range 16 V to 79.2 V

　　• Measures up to 16 cells from 1 V to 5 V

　　– Absolute maximum cell open circuit voltage 5.5 V

　　• Balancing current up to 56 mA at 4.2 V

　　• Operating temperature –40°C to 105°C

　　The bq76PL455EVM implements the following functions:

　　• Cell voltage monitoring

　　• Cell UV and OV comparators

　　• Cell balancing

　　• Temperature and auxiliary signal monitoring

　　• Embedded control

　　• Fault monitoring

　　• Isolated differential daisy chain communications

　　• PC serial communications

　　• General purpose I/O

　　• Power supply

　　图7.bq76PL455EVM评估模块外形图

　　bq76PL455EVM评估模块材料清单(BOM):