Texas Instruments BQ27531YZFT-G1

Overview

BQ27531YZFT-G1 from Texas Instruments is a system-side battery management unit (BMU) for single-cell Li-Ion battery packs, integrating Impedance Track™ fuel gauging and charger control for bq2419x-based systems. It measures cell voltage (±1 mV offset), temperature (±1°C error), and current via 5–20 mΩ sense resistor, delivering state-of-charge (%), remaining capacity (mAh), run-time-to-empty, and state-of-health (%) with <1% SOC error across operating conditions.

For engineers reviewing the BQ27531YZFT-G1 datasheet, BQ27531YZFT-G1 pinout, BQ27531YZFT-G1 application, or BQ27531YZFT-G1 equivalent, key selection considerations include I²C interface timing compliance (400 kHz), DSBGA-15 package footprint (2.61 mm × 1.96 mm), autonomous SLEEP/HIBERNATE power modes (8 µA hibernate current), and integration with bq2419x charger controllers for multi-level charging profiles.

Technical Context

The BQ27531YZFT-G1 implements TI's patented Impedance Track algorithm using real-time coulomb counting (14-bit integrating ADC, ±10 µV offset), dual-oscillator architecture (8.389 MHz HFO + 32.768 kHz LFO), and on-chip 2.5-V LDO regulator (2.3–2.6 V output, 16 mA max). It autonomously manages battery charge/discharge cycles without host intervention by interfacing directly with bq2419x chargers via BSDA/BSCL pins.

Its functional block includes dedicated analog front-end channels for TS (thermistor), BAT (cell voltage), SRP/SRN (current sense), and BI/TOUT (battery insertion detection), all sampled by a 14-bit ADC with 125-ms conversion time. The device stores calibration data and battery profiles in 20,000-cycle flash memory with 10-year data retention, enabling adaptive aging compensation and temperature-rate inefficiency correction.

Key Specifications

Pinout & Package

Package: 15-pin DSBGA (NanoFree™), body size 2.61 mm × 1.96 mm, 0.5-mm pitch - optimized for ultra-thin, space-constrained mobile applications.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar battery fuel gauge applications.

Compared with BQ27531YZFT-G1, the YZFR-G1 offers identical functionality with verified firmware versioning, while the BQ27510-G3 reduces footprint but removes autonomous charger control-making it unsuitable for bq2419x-based reference designs requiring SHIP mode or TLC.

Availability

BQ27531YZFT-G1 is available at Aetrix Electronics and suitable for smartphone power management, tablet battery monitoring, digital camera battery systems, and handheld industrial terminal applications requiring stable component supply and long-term lifecycle support.

Supply support for BQ27531YZFT-G1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor company headquartered in Dallas, Texas, specializing in analog, embedded processing, and power management technologies with broad industrial and consumer design expertise.

The BQ27531YZFT-G1 belongs to TI's Impedance Track™ battery fuel gauge product line, designed specifically for system-side integration in space-constrained portable electronics requiring high-accuracy, autonomous battery management with charger coordination.

FAQ

What is the primary function of the BQ27531YZFT-G1 in a battery management system?

The BQ27531YZFT-G1 serves as a system-side battery management unit that combines Impedance Track™ fuel gauging and autonomous charger control for single-cell Li-Ion batteries. It provides real-time state-of-charge (%), remaining capacity (mAh), run-time-to-empty, and state-of-health (%) while directly managing bq2419x chargers via BSDA/BSCL pins-eliminating host processor dependency for critical battery functions.

Does the BQ27531YZFT-G1 require an external sense resistor, and what value range is supported?

Yes, the BQ27531YZFT-G1 requires an external current-sense resistor connected between SRP and SRN pins. It supports values from 5 mΩ to 20 mΩ, enabling precise coulomb counting with ±10 µV input offset and 14-bit resolution. This low-value range minimizes power loss and thermal impact in high-current portable applications.

How does the BQ27531YZFT-G1 interface with the bq2419x charger controller?

The BQ27531YZFT-G1 interfaces with the bq2419x charger controller through dedicated BSDA (data) and BSCL (clock) pins, forming an independent I²C bus separate from the system I²C. This allows autonomous charge profile execution-including temperature-level charging (TLC) and multilevel algorithms-without host intervention or bus arbitration conflicts.

What power-saving modes does the BQ27531YZFT-G1 support, and what are their typical current draws?

The BQ27531YZFT-G1 supports five power modes: NORMAL (118 µA), SLEEP+ (62 µA), SLEEP (62 µA), HIBERNATE (8 µA), and BAT INSERT CHECK. These modes automatically transition based on load current, communication activity, or battery presence-enabling ultra-low quiescent current during storage or idle periods while maintaining fast wake-up response.

Can the BQ27531YZFT-G1 operate with both external thermistors and its internal temperature sensor?

Yes, the BQ27531YZFT-G1 supports dual thermal sensing: external NTC thermistors (e.g., 10.0 kΩ ±1%, B25/85 = 3435 K) via TS and BI/TOUT pins, or its internal temperature sensor. When using external sensing, a 18.2-kΩ pullup between BI/TOUT and TS is required. Internal sensing provides fallback capability if external components fail or are omitted in simplified designs.

Is the BQ27531YZFT-G1 pin-compatible with other members of the BQ27531-G1 family?

Yes, the BQ27531YZFT-G1 is pin-compatible with all variants in the BQ27531-G1 family-including BQ27531YZFR-G1-using the same 15-pin DSBGA (YZF) package. Differences are limited to firmware version and factory programming; no PCB layout changes are needed when substituting within this family for qualification or production flexibility.