1 Features

? AEC-Q100 qualified –40°C to +125°C

? Functional safety - compliant targeted

– Documentation to aid ISO 26262 system design

– Systematic capability up to ASIL D targeted

– Hardware capability up to ASIL D targeted

? 17 single-ended voltage channels

– High voltage pack, link, charge measurement

accuracy <0.2

– Pack and cell VI sync to 64uS

? 2 independent current sense ADCs (BQ79731-Q1)

– ±0.05 gain error drift

– Input range = ±275 mV

? 2 Over current detect comparators (BQ79731-Q1)

– ±1 accuracy

– Selectable bi-directional thresholds

– Programmable OC

? Integrated Coulomb counting (BQ79731-Q1)

? 15 GPIO inputs as IO, I2C, SPI, ADC and temp

sense

? Dedicated MOSFET switch drive pins

? Intelligent SPI contoller HUB

– Support multiple SPI peripheral devices

– HW pin to trigger contactor drivers and Pyro

Fuse drivers

? Stackable and register map compatible with with

cell monitors like the 18S (BQ79718)

2 Applications

? Full Electric, Plug-In Hybrid, Hybrid Vehicles

3 Description

The device can be used to measure divided

down high voltage nodes in a battery system. It

can measure voltage across Fuse, Contactors and

check isolation voltage in battery junction box (BJB)

system. The device has two integrated current

sense (BQ79731-Q1) paths supporting low side shunt

resistor. Coulomb counting (BQ79731-Q1) function is

available for accurate SOC calculation. There are

15 GPIOs/auxiliary inputs that can be used for HV

measurements, thermistor measurements and driving

relays. There are 4 SW outputs that can be used to

drive MOSFET switches in the measurement path.

The device can function as a SPI HUB and interface

with upto 8 separate SPI devices/groups. Over current

protection response can be achieved autonomously

using HW Pins for fast protection in dangerous over

current events. The isolated bi-directional daisy chain

ports support both capacitor and transformer based

isolation. The device can also communicate with MCU

over SPI.