Battery Fuel Gauge with Integrated Protector for 1-2 Series Packs

The Texas Instruments BQ28Z610-R1 is a highly integrated, accurate, 1-series to 2-series cell gas gauge and protection solution, enabling autonomous charger control and cell balancing. The BQ28Z610-R1 enables autonomous charge control through Master Mode I2C broadcasts of charging current and voltage information, eliminating software overhead that is typically incurred by the system’s host controller.

The BQ28Z610-R1 provides a fully integrated pack-based solution with a flash programmable custom reduced instruction-set CPU (RISC), safety protection, and authentication for 1- to 2-series cell Li-Ion and Li-Polymer battery packs.

The BQ28Z610-R1 gas gauge communicates via an I2C compatible interface and combines an ultra-low-power, high-speed TI BQBMP processor, high-accuracy analog measurement capabilities, integrated flash memory, an array of peripheral and communication ports, an N-CH FET drive, and a SHA-1 Authentication transform responder into a complete, high-performance battery management solution.

The BQ28Z610-R1 device provides an array of battery and system safety functions, including overcurrent in discharge, short circuit in charge, and short circuit in discharge protection for the battery, as well as FET protection for the N-channel FETs, internal AFE watchdog, and cell balancing. Through firmware, the devices can provide a larger array of features including protection against overvoltage, undervoltage, overtemperature, and more.

Summary of Features

• Autonomous battery charging control, using a dedicated MASTER mode I2C interface
• Cell balancing with an internal bypass to optimize battery health
• A high-side protection N-CH FET drive enables serial bus communication during fault conditions
• Programmable protection levels for voltage, current, and temperature
• Analog front-end with two independent ADCs
• Support for simultaneous current and voltage sampling
• High-accuracy coulomb counter with input offset error < 1 µV (typical)
• Supports down to 1-mΩ current sense resistor while capable of 1-mA current measurement
• Supports battery trip point (BTP) function for Windows® integration
• SHA-1 authentication responder for increased battery pack security
• 400-kHz I2C bus communications interface for high-speed programming and data access
• Compact 12-pin VSON package (DRZ)

BQ28Z610-R1 block diagram