1 Features
• Supports high-side and low-side current sense
resistors down to 1 mΩ
• Supports pack-side gauging including enhanced
state of health (SOH) algorithm
• Fast QMax update option based on predicted OCV
• SHA-256 authentication responder for increased
battery pack security
• Sophisticated charge algorithms
– JEITA
– Enhanced charging
– RSOC() charging compensation option
• 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
• Wide-range current applications (1 mA to > 5 A)
• Active high or low pulse or level interrupt pin
• Supports battery trip point (BTP)
• Reduced power modes (typical battery pack
operating range conditions)
– Typical SLEEP mode: < 11 μA
– Typical DEEP SLEEP mode: < 9 μA
– Typical HIBERNATE mode: < 3 μA
– Typical OFF mode: < 1.9 μA
• Internal and external temperature sense functions
• Diagnostic lifetime data monitor and black box
recorder
• 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
• Smartphones
• Digital still cameras and video cameras
• Tablet computing
• Portable and wearable health devices
• Portable audio devices

3 Description
The Texas Instruments BQ27Z561-R2 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-R2 gas gauge communicates through
I2C-compatible 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.