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BQ27421YZFR-G1B

TIBQ27421YZFR-G1B

Texas Instruments
Battery Battery Monitor IC Lithium Ion 9-DSBGA
Active5,278 in stock
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Overview

The BQ27421YZFR-G1B is a system-side fuel gauge for single-cell Li-Ion batteries featuring Texas Instruments patented Impedance Track technology. It integrates a low-value 7 mOhm sense resistor and a dedicated LDO to simplify power management and minimize PCB footprint in space-constrained designs.

Why Choose This Part

The integrated 7 mOhm sense resistor reduces external component count and layout complexity while maintaining high measurement accuracy. Its Impedance Track algorithm automatically adjusts for battery aging and temperature changes without requiring extensive characterization of the battery chemistry.

Applications

Wearable Devices
Ideal for smartwatches and fitness trackers where the ultra-small 9-DSBGA package and low 93 uA operating current are critical.
Handheld Medical Instruments
Provides accurate State-of-Charge and State-of-Health monitoring for portable diagnostic tools using internal temperature sensing.
Smart Home IoT Sensors
Ensures long battery life in wireless nodes by utilizing a 0.6 uA shutdown mode and configurable battery-low interrupt warnings.

Key Specifications

Function Battery Monitor
Interface I2C
Mounting Type Surface Mount
Package / Case 9-UFBGA, DSBGA
Number of Cells 1
Battery Chemistry Lithium Ion
Operating Temperature -40degC ~ 85degC (TA)
Supplier Device Package 9-DSBGA

Getting Started

Connect the IC via its 400-kHz I2C interface to any standard microcontroller and use TI's Gauge Studio software for initial configuration. Engineers should utilize the BQ27421EVM-G1A evaluation module to verify fuel gauging performance and optimize register settings for their specific battery capacity.

Also Consider

MAX17048 Analog Devices / Maxim Integrated - Offers ModelGauge technology that does not require a sense resistor, further reducing board space requirements.
BQ27441-G1 TITexas Instruments - Provides a similar integrated sense resistor design in a larger, easier-to-assemble 12-pin SON package for non-BGA workflows.
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