Overview：

The BQ79718B-Q1 is a functional safety-compliant automotive 18S battery monitor designed for high-voltage battery management systems (BMS) in xEV/EV applications. It provides high-accuracy cell voltage measurements for up to 18 series-connected battery modules, with pin-to-pin compatible channel options that support reuse of established software and hardware across platforms. The device features a dedicated ADC with typical ±1mV accuracy and synchronizes cell voltage and pack current measurements to 64µs, meeting stringent automotive safety and performance requirements. It is designed for centralized or distributed architectures in xEV powertrains, with daisy-chain isolation via transformer or capacitor.

Features：

AEC-Q100 qualified: temperature grade 1 (–40°C to +125°C), HBM ESD level 2, CDM ESD level C1.

Functional Safety-Compliant: documentation to aid ISO 26262 system design; systematic and hardware capability up to ASIL D.

Measures 9 to 18 batteries in series per device, stackable up to 64 devices.

Dedicated ADC with typical ±1mV accuracy.

Cell voltage and battery pack current measurement synchronized to 64µs.

Supports limp home mode with full redundancy.

Integrated post-ADC configurable digital low-pass filters.

Supports busbar without affecting measurement accuracy.

12 GPIOs for temperature sensor, analog, digital, I2C controller, or SPI controller.

Internal cell balancing: 300mA balancing, user-controlled PWM adjustment of balancing current, built-in thermal management with automatic pause and resume.

Robust daisy-chain communication with ring architecture support.

Hardware reset by host simulates POR-like event without battery removal.

Supports transformer and capacitive isolation.

On-chip memory for one-time custom programming.

Low-power mode current <6µA.

Compatible with BQ79600-Q1 via SPI/UART interface.

Package: 64-pin HTQFP (PAP), 10mm × 10mm.

Applications:

xEV/EV high-voltage battery management systems (BMS).

Centralized or distributed BMS architectures in xEV powertrains.

Wired cell monitoring units with isolated differential daisy-chain.

Wireless cell monitoring units when paired with wireless BMS MCU-11

Wired and wireless high-voltage battery systems