Automotive high-voltage battery pack monitor with voltage, current and insulation resistance sensing

BQ79731B-Q1 can be used to measure divided down high voltage nodes in a

battery system. The device can measure voltage across Fuse, Contactors and check

isolation voltage in a battery junction box (BJB) system. The device has two

integrated current sense paths supporting low-side shunt resistor. Coulomb counting

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 four 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 up to

eight 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 and UART.