1 Features

1• Supports current sense resistors down to 1 mΩ

• SHA-256 authentication responder for increased

battery pack security

• Two independent ADCs

– Support for simultaneous current and voltage

sampling

– High-accuracy coulomb counter with input

offset error < 1 μV (typical)

• Low-voltage (2 V) operation

• Supports pack-side gauging

• Wide-range current applications (1 mA to > 5 A)

• Active high or low interrupt pin

• Reduced power modes (typical battery pack

operating range conditions)

– Typical SLEEP mode: < 11 μA

– Typical DEEP SLEEP mode: < 9 μA

– Typical OFF mode: < 1.9 μA

• Internal and external temperature sense functions

• 400-kHz I2C bus communications interface for

high-speed programming and data access

• HDQ one-wire for communication with host

• Compact 12-pin DSBGA package (YPH)

2 Applications

• Smart phones

• Digital still and video cameras

• Tablet computing

• Portable and wearable health devices and

portable audio devices

3 Description

The Texas Instruments BQ27Z561 Impedance

Track™ gas gauge solution is a highly integrated,

accurate 1-series cell gas gauge with a flash

programmable custom reduced instruction-set CPU

(RISC) and SHA-256 authentication for Li-Ion and Li-

Polymer battery packs. The 1-series cell capability

includes parallel cells for increased capacity.

The BQ27Z561 gas gauge communicates via I2Ccompatible

and HDQ one-wire interfaces and

includes several key features that can help facilitate

accurate gas gauging applications. Integrated

temperature sense functions (internal and external

options) enable system and battery temperature

measurements. The integrated SHA-256 functionality

helps enable secure identification between systems

and packs. The interrupt function facilitates the

BQ27Z561 device to inform the system when a stateof-

charge (SOC), voltage, or temperature fault

occurs. The low-voltage operation enables the

system to continue monitoring the battery even in

deeply discharged conditions. During low-activity

situations, the device can be set to the low power

coulomb counting (CC) mode, which allows the

device to continue its coulomb counting while

reducing operating current significantly.