1 Features

• Device qualified with the following results:

– Device temperature grade 1: –40°C to +125°C

ambient operating temperature range

– Device HBM ESD classification level 2

– Device CDM ESD classification level C1

• Functional Safety-Compliant

– Documentation to aid ISO 26262 and IEC

61508 system design

– Systematic capability up to ASIL B and SIL2

– Hardware intergity up to ASIL B and SIL 2

• Measure 9 to 18 batteries in series per device,

stackable up to 64 devices

• Dedicated ADC with ±3.0mV accuracy for 1-5V

input (-40°C to +125°C)

• Cell voltage and battery pack current

measurement synchronized to 64μs

• Support limp mode with full redundancy

• Integrated post-ADC configurable digital low-pass

filters

• Supports busbar without affecting measurement

accuracy

• 12 GPIOs for temp sensor/analog/digital/I2C

controller/SPI controller

• Internal cell balancing

– Balancing at 300mA

– User controlled PWM adjustment cell balancing

current

– Built-in balancing thermal management with

automatic pause and resume control

• Robust daisy chain communication and support

Ring Architecture

• Hardware reset by host simulates POR-like event

without battery removal

• Support transformer and capacitive isolation

• On chip memory for one time custom programming

• Low power mode current <6μA

• Compatible with BQ79600-Q1 with SPI/UART

interface

2 Applications

• Energy storage systems

3 Description

The BQ78702B provides high-accuracy cell voltage

measurements for up to 18S battery modules in

high-voltage battery management systems in energy

storage systems. This device has a state-of-theart

ADC architecture/measurement system meeting

stringent safety requirements. With the daisy-chain

isolated by transformer (or capacitor), the device

is designed for centralized or distributed system

architectures.