1 Features

• Single-cell Li-ion battery fuel gauge

– Resides on system board

– Supports embedded or removable batteries

– Powers directly from the battery with integrated

LDO

– Supports a low-value external sense resistor

(10 mΩ)

• Ultra low 9 μA operating current when the load is

below 10 mA, set by Sleep Current threshold.

• Battery fuel gauging based on patented

Impedance Track™ technology

– Provides three selectable preprogrammed

profiles for 4.2-V, 4.35-V, and 4.4-V cells

– Reports remaining capacity and state-of-charge

(SOC) with smoothing filter

– Adjusts automatically for battery aging, selfdischarge,

temperature, and rate changes

– Estimates battery state-of-health (aging)

• Microcontroller peripheral interface supports:

– 400-kHz I2C serial interface

– Configurable SOC interrupt or

battery low digital output warning

– Internal temperature sensor or host reported

temperature or external thermistor

2 Applications

• Smartphones, feature phones, and tablets

• Wearables

• Building automation

• Portable medical/industrial handsets

• Portable audio

• Gaming

3 Description

The Texas Instruments BQ27426 battery fuel gauge

is a single-cell gauge that requires minimal userconfiguration

and system microcontroller firmware

development, leading to quick system bring-up.

Three chemistry profiles are preprogrammed to

enable minimum user-configuration, and to help

manage customer inventory across projects with

different battery chemistries. The BQ27426 battery

fuel gauge has very low sleep power consumption

leading to longer battery run time. Configurable

interrupts help save system power and free up the

host from continuous polling. Accurate temperature

sensing is supported via an external thermistor.

The BQ27426 battery fuel gauge uses the patented

Impedance Track™ algorithm for fuel gauging, and

provides information such as remaining battery

capacity (mAh), state-of-charge (%), and battery

voltage (mV).

Battery fuel gauging with the BQ27426 fuel gauge

requires connections only to PACK+ (P+) and PACK–

(P–) for a removable battery pack or embedded

battery circuit. The tiny, 9-ball, 1.62 mm × 1.58

mm, 0.5 mm pitch NanoFree™ chip scale package

(DSBGA) is ideal for space-constrained applications.