Texas Instruments BQ27320YZFT

Overview

BQ27320YZFT from Texas Instruments is a single-cell Li-ion battery fuel gauge IC implementing Compensated End-of-Discharge Voltage (CEDV) algorithm for accurate state-of-charge (SOC), remaining capacity (mAh), time-to-empty (min), and state-of-health estimation. It supports 100–14,500 mAh battery packs, operates from –40°C to 85°C, and interfaces via 400-kHz I²C and SDQ protocols. It is used in space-constrained portable electronics requiring precise battery telemetry without host firmware overhead.

For engineers reviewing the BQ27320YZFT datasheet, BQ27320YZFT pinout, BQ27320YZFT application, or BQ27320YZFT equivalent, key selection considerations include its CEDV-based gauging accuracy across aging/temperature/rate variations, dual temperature sensing (external thermistor or internal sensor), integrated 2.5-V LDO, 15-ball NanoFree™ DSBGA package, and support for up to four swappable battery profiles.

Technical Context

The BQ27320YZFT performs real-time coulomb counting using a 14–15-bit integrating ADC with ±10 µV input offset and 125-ms conversion time for voltage/temperature, plus 1-s conversion for current sense. Its CEDV algorithm models cell OCV as a function of SOC, temperature, and current using seven calibrated parameters (EMF, C0, R0, T0, R1, TC, C1), enabling runtime prediction under dynamic load and aging conditions.

It integrates a 2.5-V LDO (2.3–2.6 V output, 16 mA max), dual oscillators (8.389 MHz HF, 32.768 kHz LF), 32-byte scratch-pad FLASH NVM, and configurable interrupts (SOC_INT, BAT_GD). Power management includes five operational modes-NORMAL (118 µA), SNOOZE (62 µA), SLEEP (23 µA), HIBERNATE (8 µA), and SHUTDOWN (1 µA)-triggered automatically or by host command.

Key Specifications

Pinout & Package

The BQ27320YZFT is housed in a 15-ball NanoFree™ (DSBGA) package with 0.4-mm pitch, optimized for ultra-low-profile, high-density PCB layouts in portable devices.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ27426YZFT, the BQ27320YZFT offers proven field reliability and simpler calibration but lacks newer thermal modeling and lower-power sleep modes; versus BQ27220YZFT, it adds critical security and status signaling features required for modern portable systems.

Availability

BQ27320YZFT is available at Aetrix Electronics and suitable for smartphones, wearables, and portable medical handsets requiring stable component supply, long-lifecycle support, and consistent parametric performance across production batches.

Supply support for BQ27320YZFT 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 leader specializing in analog, embedded processing, and power management technologies, with decades of expertise in battery management solutions.

The BQ27320YZFT belongs to TI's CEDV-based fuel gauge product line, designed specifically for single-cell Li-ion systems where high-accuracy runtime prediction, minimal host firmware dependency, and compact packaging are essential.

FAQ

What is the primary gauging algorithm used by the BQ27320YZFT?

The BQ27320YZFT implements the Compensated End-of-Discharge Voltage (CEDV) algorithm, which models cell open-circuit voltage as a function of state-of-charge, temperature, and current using seven calibrated parameters. This enables accurate SOC and time-to-empty estimation across battery aging, self-discharge, and varying load conditions-without requiring full discharge cycles for learning. The BQ27320YZFT uses this method to deliver ±5% SOC accuracy over the battery lifetime.

Does the BQ27320YZFT support external thermistor sensing?

Yes, the BQ27320YZFT supports external NTC thermistor sensing via the TS and BI/TOUT pins, optimized for 10.0 kΩ ±1% thermistors like the Semitec 103AT (B25/85 = 3435K). A 18.2-kΩ pull-up resistor between BI/TOUT and TS is required. The device also supports internal temperature sensing or host-reported temperature, allowing flexible thermal monitoring based on system architecture and accuracy requirements for the BQ27320YZFT.

What communication interfaces does the BQ27320YZFT provide?

The BQ27320YZFT provides two digital interfaces: a 400-kHz I²C-compatible serial interface (SCL/SDA) for high-speed telemetry read/write, and a single-wire SDQ interface (SDQ pin) for authentication ID communication with companion security ICs. Both interfaces operate independently-the I²C bus handles fuel gauge data (e.g., RemainingCapacity(), SOC(), Temperature()), while SDQ manages secure identification. No shared resources or arbitration logic is required between them in the BQ27320YZFT.

How does the BQ27320YZFT handle multiple battery profiles?

The BQ27320YZFT stores up to four independent battery profiles in its data flash memory, enabling seamless swapping of different removable battery packs without host reconfiguration. Each profile retains unique chemistry parameters, learned full-charge capacity, and aging data. Profile selection is performed via Control() subcommands (BATT_SELECT_0 through BATT_SELECT_3), allowing the host to switch contexts dynamically. This capability is integral to the BQ27320YZFT's design for consumer electronics with interchangeable batteries.

What power-saving modes does the BQ27320YZFT support?

The BQ27320YZFT supports five power modes: NORMAL (118 µA), SNOOZE (62 µA), SLEEP (23 µA), HIBERNATE (8 µA), and SHUTDOWN (1 µA). Mode transitions occur automatically based on activity (e.g., no I²C traffic triggers SLEEP) or can be forced via Control() subcommands (SET_SNOOZE, CLEAR_HIBERNATE, etc.). The CE pin disables the internal LDO to enter SHUTDOWN. These modes allow the BQ27320YZFT to minimize system-level power consumption while maintaining accurate gauging fidelity during active use.