BQ27Z855
Single-cell Dynamic Z-Track™ fuel gauge with protector, current limiter and authentication
BQ27Z855
- Fully integrated battery gas gauge, protector, current limiter, and authenticator
- Ultra-low power 32-bit RISC processor
- Battery chemistries supported include Li-ion with LCO, NMC, or LFP cathodes and with graphite or Si-anodes
- High-accuracy analog front end with two independent ADCs:
- 18-bit low offset delta-sigma ADC for Coulomb counting with ±100mV input range
- 16-bit delta-sigma ADC for cell voltage and internal and external temperature sensors
- Support for simultaneous current and voltage sampling
- High-side or low-side current sensing for system flexibility
- Battery fuel gauging based on patented Dynamic Z-Track technology
- Models battery impedance for accurate time-to-empty predictions for static and dynamic loads
- Automatically adjusts for aging, temperature, and rate-induced effects on the battery
- Programmable safety and protection:
- Hardware- and firmware-level OVP, UVP, OCC, OCD, SCD protections
- Overtemperature (OT) and undertemperature (UT) protections
- Integrated high efficiency high-side NMOS protection FET drivers
- Current limiter with programmable CC-CV profile during charge mode
- Ideal diode controller during discharge mode
- Up to 1MHz I2C bus communications interface with 1.2V- and 1.8V-level support
- ECC ECDSA and SHA-256 authentication support with secure memory
- Ultra-compact, 15-ball DSBGA package (YAH)
The Texas Instruments BQ27Z855 Dynamic Z-Trackgas gauge solution is a fully integrated, accurate 1-series cell gas gauge, protection, current limiter, and authentication solution.
The BQ27Z855 device provides a fully integrated pack-based solution with a flash programmable reduced instruction-set CPU (RISC), safety protection, current limiter, ideal diode controller, and authentication for 1-series cell Li-ion and Li-polymer battery packs.
The BQ27Z855 gas gauge communicates through an I2C compatible interface and combines an ultra-low power RISC processor, high accuracy analog measurement capabilities, integrated flash memory, high-side NMOS FET drivers, and ECC ECDSA and SHA-2 authentication to provide a complete, high-performance battery management solution.
Technical documentation
| Top documentation | Type | Title | Format options | Date |
|---|---|---|---|---|
| * | Data sheet | BQ27Z855 Dynamic Z-Track™ Technology Battery Gas Gauge and Protection Solution for Single Cell Li-Ion Battery datasheet | PDF | HTML | 12 Feb 2026 |
| Application note | Dynamic Z-Track™ Technology: An Advanced Battery Gauging Algorithm for Dynamic Load Applications (Rev. A) | PDF | HTML | 15 Jul 2025 | |
| Application note | Implementation of Elliptic Curve Cryptography Authentication on TI Battery Fuel Gauges | PDF | HTML | 28 May 2025 | |
| Application note | How to Create and Program Authentication Keys into TI Battery Fuel Gauges | PDF | HTML | 05 Mar 2025 | |
| User guide | BQ27Z855 Technical Reference Manual | PDF | HTML | 28 Feb 2025 | |
| Application note | Battery Gauging Algorithm Comparison | PDF | HTML | 04 Dec 2023 |
Design & development
For additional terms or required resources, click any title below to view the detail page where available.
BQ27Z855EVM — BQ27Z855EVM evaluation module
The BQ27Z855 Evaluation Module (EVM) is a system-level board created to enable users to evaluate the functionalities of the BQ27Z855 fuel gauge within their system. The BQ27Z855 EVM is suitable for applications in which the battery pack is 1-S cell, meaning one series cell. The EVM includes a (...)
BQ27Z855-FW — BQ27Z855 device firmware
Supported products & hardware
BQSTUDIO-GUI — Battery Management Studio (bqStudio) Software - Web Based Version
Battery Management Studio (bqStudio) offers a full suite of robust tools to assist with the process of evaluating, designing with, configuring, testing, or otherwise utilizing TI Battery management products. This includes features that provide full access to registers and data memory including (...)
Supported products & hardware
BQ-BMS-PROGRAMMER-SW — Command line programmers for BQ products
BQ-BATTERY-PROGRAMMER-SW software development kit (SDK) is a collection of robust software command line tools that assist with the process of programming, testing, or assembling packs that use TI Battery management products. The executables in this software work with the MKST-3P-ALT-EV2300 MKS (...)
Supported products & hardware
BQ27Z855-DS — BQ27Z855 Documentation
Supported products & hardware
BQAMBER-SIM-TOOL — BGP release page for BQAMBER-SIM-TOOLS
Supported products & hardware
| Package | Pins | CAD symbols, footprints & 3D models |
|---|---|---|
| DSBGA (YAH) | 15 | Ultra Librarian |
Ordering & quality
- RoHS
- REACH
- Device marking
- Lead finish/Ball material
- MSL rating/Peak reflow
- MTBF/FIT estimates
- Material content
- Qualification summary
- Ongoing reliability monitoring
- Fab location
- Assembly location
Support & training
TI E2E™ forums with technical support from TI engineers
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