Texas Instruments BQ27320YZFR

Overview

BQ27320YZFR 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 packs, accommodates up to four battery profiles, and interfaces via 400-kHz I²C or SDQ for authentication. Used in space-constrained portable electronics requiring precise battery telemetry.

For engineers reviewing the BQ27320YZFR datasheet, BQ27320YZFR pinout, BQ27320YZFR application, or BQ27320YZFR equivalent, key selection considerations include its 15-ball NanoFree™ DSBGA package, integrated coulomb counter with ±10 µV offset, dual temperature sensing (external thermistor or internal sensor), low-power SLEEP mode (23 µA), and CEDV-based aging compensation across –40°C to 85°C.

Technical Context

The BQ27320YZFR performs real-time voltage, current (via Kelvin-connected SRP/SRN pins), and temperature measurement to execute the CEDV gas-gauging algorithm-modeling OCV as a function of SOC, temperature, and current using seven calibrated parameters (EMF, C0, R0, T0, R1, TC, C1). It integrates charge/discharge current with 14–15-bit resolution and <±0.034% FSR INL.

It operates in five power modes (NORMAL, SNOOZE, SLEEP, HIBERNATE, BAT INSERT CHECK), auto-switching based on activity; features a 2.5-V LDO (2.3–2.6 V output), 8.389-MHz high-frequency oscillator, and 32.768-kHz low-frequency oscillator for timing-critical gauging functions. All data-including Design Capacity, FCC, and chemistry parameters-is stored in 32-byte scratch-pad FLASH NVM with 10-year retention and 20,000 write cycles.

Key Specifications

Pinout & Package

15-ball NanoFree™ DSBGA (YZF) package with 0.4-mm pitch; 1.375 mm × 2.75 mm body size and 1.75-mm height. Designed for minimal PCB area and low thermal resistance (R_θJA = 70°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ27320YZFR, BQ27426YZFT adds cryptographic security and extended memory at higher BOM cost and firmware complexity, while BQ27220YZFT reduces feature set and power flexibility-making BQ27320YZFR the optimal balance of accuracy, configurability, and integration for mainstream portable electronics.

Availability

BQ27320YZFR is available at Aetrix Electronics and suitable for smartphones, wearables, and portable medical handsets requiring stable component supply, long-term lifecycle support, and consistent performance across production batches.

Supply support for BQ27320YZFR 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, delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The BQ27320YZFR belongs to TI's battery fuel gauge product line, designed specifically for accurate, low-power, single-cell Li-ion state estimation in space-constrained portable devices-emphasizing CEDV algorithm robustness, multi-profile flexibility, and minimal host firmware dependency.

FAQ

What is the primary gauging algorithm used by the BQ27320YZFR?

The BQ27320YZFR implements the Compensated End-of-Discharge Voltage (CEDV) algorithm, which models open-circuit voltage as a function of state-of-charge, temperature, and current using seven calibrated parameters (EMF, C0, R0, T0, R1, TC, C1). This enables accurate SOC estimation across battery aging, self-discharge, and varying load conditions without requiring periodic full-discharge recalibration. The BQ27320YZFR executes this algorithm autonomously using on-chip processing and integrated ADCs.

Does the BQ27320YZFR support external thermistor sensing?

Yes, the BQ27320YZFR supports external thermistor sensing via the TS pin and BI/TOUT pin, optimized for a 10.0 kΩ NTC thermistor with B25/85 = 3435K (e.g., Semitec 103AT). A 18.2-kΩ pull-up resistor between BI/TOUT and TS is required. It also supports internal temperature sensing or host-reported temperature-providing design flexibility for thermal accuracy versus component count trade-offs in the BQ27320YZFR implementation.

What are the power modes supported by the BQ27320YZFR and their typical current draw?

The BQ27320YZFR 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 or can be triggered via I²C commands like SET_SNOOZE or CLEAR_HIBERNATE. These low quiescent currents make the BQ27320YZFR suitable for battery-operated devices requiring weeks of standby time, such as wearables and remote sensors.

Can the BQ27320YZFR be used with multiple battery profiles?

Yes, the BQ27320YZFR supports up to four independent battery profiles, selectable via I²C subcommands BATT_SELECT_0 through BATT_SELECT_3. Each profile stores unique chemistry parameters, capacity settings, and calibration data in FLASH-enabling seamless swapping of different Li-ion cells (e.g., varying capacities or aging states) without host firmware modification. This capability is integral to the BQ27320YZFR's architecture for modular and serviceable battery systems.

What communication interfaces does the BQ27320YZFR provide?

The BQ27320YZFR provides two communication interfaces: a 400-kHz I²C-compatible serial interface (SCL/SDA) for high-speed bidirectional data exchange with the host MCU, and a single-wire SDQ interface (SDQ pin) for authentication ID IC communication. Both interfaces are electrically and logically distinct-SDQ handles secure identification, while I²C manages all fuel gauge data reads/writes, configuration, and control commands in the BQ27320YZFR.