BQ79735-Q1

The BQ79735-Q1 is a high-precision, automotive-grade battery management system (BMS) IC designed for monitoring and managing multi-cell lithium-ion battery packs. It supports up to 16 cells in series with a maximum cell voltage measurement accuracy of ±2 mV, ensuring reliable state-of-charge (SoC) and state-of-health (SoH) estimation. The device features integrated analog-to-digital converters (ADCs), precision shunt resistors, and dedicated charge/discharge current sensing for accurate current measurement within ±0.5% error over temperature. This IC includes robust safety mechanisms such as overvoltage, undervoltage, overtemperature, and short-circuit protection, making it suitable for demanding automotive environments. Its internal microcontroller unit (MCU) enables advanced diagnostics, including cell balancing, fault detection, and communication protocol handling. The BQ79735-Q1 supports both CAN and I2C communication interfaces, allowing seamless integration into vehicle networks and enabling real-time data exchange with the vehicle’s central control unit. Designed for compliance with AEC-Q100 Grade 1 qualification, the BQ79735-Q1 operates reliably across an extended temperature range from -40°C to +125°C. It features low quiescent current (<10 µA in sleep mode), enhancing energy efficiency in battery-powered systems. The device also incorporates redundant ADC channels and self-test capabilities to meet functional safety requirements per ISO 26262 ASIL-B standards. Its scalable architecture allows flexible configuration for various battery pack topologies, supporting both single- and dual-supply designs. The BQ79735-Q1 integrates cell balancing circuits using a high-side switch topology, reducing external component count while maintaining efficient balancing performance. Additionally, it provides programmable thresholds, hysteresis, and timing parameters through software configuration, offering design flexibility for diverse applications. Common applications include electric vehicles (EVs), hybrid electric vehicles (HEVs), energy storage systems, and industrial battery packs where high reliability, precise monitoring, and functional safety are critical. The BQ79735-Q1 is ideal for use in traction battery systems requiring long-term stability, fault tolerance, and compliance with automotive standards.