Texas Instruments BQ27220YZFT

Overview

BQ27220YZFT from Texas Instruments is a single-cell Li-ion battery fuel gauge IC using Compensated End-of-Discharge Voltage (CEDV) algorithm. It resides in the battery pack or on the system board, powers directly from the battery via integrated 1.8-V LDO, supports 10-mΩ external sense resistor, and reports remaining capacity (mAh), state-of-charge (%), runtime-to-empty (min), voltage (mV), temperature (°C), and state-of-health (%). It targets space-constrained portable electronics requiring accurate, low-power fuel gauging.

For engineers reviewing the BQ27220YZFT datasheet, BQ27220YZFT pinout, BQ27220YZFT application, or BQ27220YZFT equivalent, key selection considerations include ultra-low power consumption (50 µA NORMAL / 9 µA SLEEP), I²C interface timing compliance (400 kHz Fast Mode), CEDV-based aging compensation, integrated LDO regulation, and DSBGA-9 package compatibility with high-density PCB layouts.

Technical Context

The BQ27220YZFT implements a CEDV-based fuel gauging model that correlates open-circuit voltage (OCV), temperature, current, and impedance to estimate remaining capacity - requiring full discharge for FCC update. Its integrating ADC provides 16-bit resolution for coulomb counting across SRP/SRN differential inputs, while a separate 15-bit ADC measures BAT voltage and temperature.

It operates in three functional modes: INITIALIZATION (firmware boot), NORMAL (active gauging), and SLEEP (ultra-low-power monitoring), with automatic transitions triggered by I²C activity or wake events. The GPOUT pin serves dual roles - configurable as BAT_LOW interrupt or SOC_INT pulse output - and functions as a wake-up input when pulled high during SHUTDOWN mode.

Key Specifications

Pinout & Package

Package: DSBGA-9 (NanoFree™ chip-scale), 1.62 mm × 1.58 mm, 0.5-mm pitch - optimized for ultra-compact battery pack or system-board integration.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ27220YZFT, BQ27426YZFT adds hardware protection control but increases size and complexity, while BQ27510-G3YZFT offers superior long-term aging modeling at the cost of host firmware involvement and reduced out-of-box simplicity.

Availability

BQ27220YZFT is available at Aetrix Electronics and suitable for smartphones, wearables, and portable medical handsets requiring stable component supply, long-lifecycle support, and consistent factory-programmed CEDV parameters.

Supply support for BQ27220YZFT 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 specializing in analog and embedded processing technologies, with leadership in battery management, power conversion, and signal chain solutions.

The BQ27220YZFT belongs to TI's bq27xxx fuel gauge product line, designed specifically for low-power, single-cell Li-ion applications where minimal host intervention, small form factor, and field-proven CEDV accuracy are critical.

FAQ

What is the primary fuel gauging algorithm used by the BQ27220YZFT?

The BQ27220YZFT uses the Compensated End-of-Discharge Voltage (CEDV) algorithm, which models battery open-circuit voltage as a function of state-of-charge, temperature, and current. This enables automatic compensation for aging, self-discharge, and rate effects without host calibration. The BQ27220YZFT implements this algorithm in hardware with preloaded ROM parameters or customer-defined OTP values generated via TI's GAUGEPARCAL tool.

Does the BQ27220YZFT require an external sense resistor, and what value is supported?

Yes, the BQ27220YZFT requires an external sense resistor connected between SRP and SRN pins. It is pre-calibrated for a standard 10-mΩ, 1% tolerance resistor - no calibration is needed. The device supports Kelvin connections for both system-side (SRP to PACK+, SRN to VSYS) and pack-side low-side (SRP to PACK–, SRN to Cell–) configurations, ensuring accurate coulomb counting across diverse implementations.

How does the BQ27220YZFT manage power consumption in low-duty-cycle applications?

The BQ27220YZFT achieves ultra-low power operation with 9 µA in SLEEP mode and 50 µA in NORMAL mode. It automatically transitions between INITIALIZATION, NORMAL, and SLEEP based on I²C activity and wake events. GPOUT can trigger wake-up from SHUTDOWN (0.6 µA), and configurable interrupts reduce host polling. This makes the BQ27220YZFT ideal for wearables and medical devices where battery life is constrained by quiescent current.

Can the BQ27220YZFT operate without an external microcontroller?

No - the BQ27220YZFT is a microcontroller peripheral requiring I²C host interaction for configuration, parameter loading, and data retrieval. It does not execute autonomous state-machine logic. However, it minimizes host firmware burden: default CEDV parameters are stored in ROM, OTP programming eliminates runtime setup, and standard commands (e.g., Control(), DataFlash()) abstract low-level register access. The BQ27220YZFT relies on the host for temperature reporting (if not using internal sensor or BIN thermistor) and initial OTP programming.

What package type and dimensions does the BQ27220YZFT use?

The BQ27220YZFT uses a NanoFree™ DSBGA-9 package (orderable code YZF) with nominal body size 1.62 mm × 1.58 mm and 0.5-mm ball pitch. This chip-scale construction enables direct mounting on battery flex circuits or ultra-dense system boards. The package has nine solder balls arranged in a 3×3 grid, with VSS (B2), VDD (B3), BAT (C3), SRP (C1), SRN (C2), SCL (A3), SDA (A2), GPOUT (A1), and BIN (B1) - verified from TI's official pinout diagram and mechanical drawings.