Product details


Number of series cells 1, 2, 3, 4, 5 Charge current (Max) (A) 16.2 Operating Vin (Max) (V) 26 Cell chemistry Lead Acid, Li-Ion/Li-Polymer, Lithium Phosphate/LiFePO4, NiCd, NiMH, SuperCap Battery charge voltage (Min) (V) 1.024 Battery charge voltage (Max) (V) 23 Absolute Vin (safety rating) (Max) ((V)) 32 Control topology Switch-Mode Buck-boost Control interface I2C Features IC thermal regulation, ICO (Input Current Optimization), IINDPM (Input current limit), Input OVP, Integrated ADC, USB C/PD compatible, USB OTG integrated, VINDPM (Input voltage threshold to maximize adaptor power) Operating Vin (Min) (V) 3.5 Rating Catalog open-in-new Find other Battery charger ICs

Package | Pins | Size

WQFN (RSN) 32 16 mm² 4 x 4 open-in-new Find other Battery charger ICs


  • No battery MOSFET for saving cost and high efficiency
  • 400-kHz/800-kHz programmable switching frequency for high efficiency/high power density
  • Buck-boost charger for USB-C Power Delivery (PD) interface platform
    • 3.5-V to 26-V input range to charge 1- to 5-cellbattery
    • Charge current up to 16.2 A/8.1 A with 128-mA/64-mA resolution based on 5-mΩ/10-mΩ sensing resistor
    • Input current limit up to 10 A/6.35 A with 100-mA/50-mA resolution based on 5-mΩ/10-mΩ sensing resistor
    • Support USB 2.0, USB 3.0, USB 3.1 and USB power delivery input current setting
    • Input Current Optimizer (ICO) to extract max input power without overloading the adapter
    • Seamless transition between buck, buck-boost, and boost operations
    • Input current and voltage regulation (IINDPM and VINDPM) against source overload
  • TI patented switching frequency dithering pattern for meeting IEC-CISPR 32 EMI specification
  • TI patented Pass Through Mode (PTM) for system power efficiency improvement and battery fast charging achieving 99% efficiency.
  • Input and battery current monitor through dedicated pins
  • Integrated 8-bit ADC to monitor voltage, current and power
  • Support independent comparator logic with dedicated pins
  • Power up USB port from battery (USB OTG)
    • 3-V to 24-V OTG with 8-mV resolution
    • Output current limit up to 12.7 A/6.35 A with 100-mA/50-mA resolution based on 5-mΩ/10-mΩ sensing resistor
  • I2C host control interface for flexible system configuration
  • High accuracy for the regulation and monitor
    • ±0.5% Charge voltage regulation
    • ±3% Charge current regulation
    • ±2.5% Input current regulation
    • ±2% Input/charge current monitor
  • Safety
    • Thermal shutdown
    • Input, system, battery overvoltage protection
    • Input, MOSFET, inductor overcurrent protection
  • Package: 32-Pin 4.0 mm × 4.0 mm WQFN
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The BQ25731 is a synchronous buck-boost battery charge controller to charge a 1- to 5-cell battery from a wide range of input sources including USB adapter, high voltage USB-C Power Delivery (PD) sources, and traditional adapters. It offers a low component count, high efficiency solution for space constrained, 1- to 5-cell battery charging applications.

During power up, the charger sets the converter to a buck, boost, or buck-boost configuration based on the input source and battery conditions. The charger seamlessly transits between the buck, boost, and buck-boost operation modes without host control.

During power up, the charger sets the converter to a buck, boost, or buck-boost configuration based on the input source and battery conditions. The charger seamlessly transits between the buck, boost, and buck-boost operation modes without host control.

In the absence of an input source, the BQ25731 supports the USB On-the-Go (OTG) function from a 1- to 5-cell battery to generate an adjustable 3-V to 24-V output on VBUS with 8-mV resolution. The OTG output voltage transition slew rate can be configured to comply with the USB-PD 3.0 PPS specification.

The latest version of the USB-C PD specification includes Fast Role Swap (FRS) to ensure power role swapping occurs in a timely fashion so that the device(s) connected to the dock can avoid experiencing momentary power loss or glitching. This device integrates FRS in compliance with the PD specification.

TI patented switching frequency dithering pattern can significantly reduce EMI noise over the whole conductive EMI frequency range (150 kHz ~ 30 MHz). Multiple dithering scale options are available to provide flexibility for different applications to simplify EMI noise filter design.

The charger can be operated in the TI patented pass through (PTM) mode to improve efficiency over the full load range. In PTM, input power is directly passed through the charger to the system. Switching losses of the MOSFETs and inductor core loss can be saved for high efficiency operation.

The BQ25731 is available in a 32-pin 4mm × 4mm WQFN package.

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More information

  • If you would like to consider a universal standards compliant, up to 20V USB Type-C PD Port to power the charger, please consider TPS25750
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NEW BQ25730 ACTIVE I²C 1-5 cell NVDC buck-boost battery charge controller with power path and USB-C® PD OTG This product has power path.

Technical documentation

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Type Title Date
* Data sheet BQ25731 I2C 1- to 5-Cell Buck-Boost Battery Charge Controller datasheet (Rev. A) Jan. 28, 2021
User guide BQ2573x Evaluation Module (Rev. A) Jan. 19, 2021
Technical article Adding USB Type-C® with USB Power Delivery to battery-powered applications Nov. 11, 2020
Certificate BQ25731EVM EU Declaration of Conformity (DoC) Jun. 19, 2020
Technical article When to use rechargeable batteries in small battery applications Oct. 01, 2019
Technical article Should I use a linear charger or a switching charger? Oct. 31, 2015
Technical article Summertime and the livin' is easy Jun. 20, 2014

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Hardware development

document-generic User guide
The BQ25731EVM evaluation module (EVM) is an I2C controlled NVDC (narrow voltage DC) buck-boost charge controller with N-channel MOSFET selector and current monitoring. The input voltage range for the buck converter is between 3.5 V and 26 V, with a programmable output of 1 to 5 cells and a charge (...)
  • Host-controlled NVDC 1S to 5S battery buck-boost charger with 3.5-V to approximately 26-V input; 1-V to approximately 23-V charging output and 3-V to approximately 24-V OTG output
  • Supports USB 2.0, USB 3.0, USB 3.1 ( USB Type-C™) and USB_PD platforms
  • Supports 5-mΩ current sense for high current (...)

Software development

Battery Management Studio (bqStudio) Software
BQSTUDIO 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 (...)
  • Real-time Gauge Dashboard for monitoring basic registers
  • Full register access and logging
  • Full data memory access and logging
  • Product configuration and monitoring tools
  • Import and export of product configurations
  • Calibration and test automation
  • Export of FS files for the target production environment 
GUI software for use with USB2ANY and battery charging evaluation modules
TI-CHARGER-GUI — The TI-CHARGER-GUI offers a web-based or standalone graphical user interface to assist in the process of evaluating, designing with, configuring or testing battery charger products. The software provides full access to registers and an easy interface to send and sequence commands.
  • Web-based or standalone GUI with easy to follow graphic instructions
  • Configures supported battery charger evaluation modules (EVMs) through USB2ANY interface adaptor
  • Easy to navigate pages organized by functional groupings
  • Supports sequenced I2C or SMBus commands

CAD/CAE symbols

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QFN (RSN) 32 View options

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