Texas Instruments bq25628E I2C Controlled Buck Battery Charger

Texas Instruments bq25628E I2C Controlled Buck Battery Charger is a highly integrated 2A switch-mode battery charge management and system power path management device for single-cell Li-ion and Li-polymer batteries. The solution includes built-in current sensing, loop compensation, and input reverse-blocking FET (RBFET, Q1). It also contains high-side switching FET (HSFET, Q2), low-side switching FET (LSFET, Q3), and battery FET (BATFET, Q4) between the system and battery. The device uses narrow VDC power path management, regulating the system slightly above the battery voltage without dropping below a configurable minimum system voltage. The low impedance power path optimizes switch-mode operation efficiency, reduces battery charging time, extends battery life during the discharging phase, and the ultra-low 0.15µA ship mode current extends battery shelf life. The I2C serial interface with charging and system settings makes the bq25628E a truly flexible solution. The Texas Instruments bq25628E is available in an 18-pin, 2.5mm × 3.0mm WQFN package.


  • High-efficiency, 1.5MHz, synchronous switching mode buck charger for single-cell battery
    • > 90% efficiency down to 25mA output current from 5V input
    • Charge termination from
    • Flexible JEITA profile for safe charging over temperature
  • BATFET control to support shutdown, ship mode, and full system reset
    • 1.5µA quiescent current in battery-only mode
    • 0.15µA battery leakage current in ship mode
    • 0.1µA battery leakage current in shutdown
  • Supports a wide range of input sources
    • 3.9V to 18V wide input operating voltage range with 26V absolute maximum input voltage
    • Maximizes source power with input voltage regulation (VINDPM) and input current regulation (IINDPM)
    • VINDPM threshold automatically tracks battery voltage
  • Efficient battery operation with 15mΩ BATFET
  • Narrow VDC (NVDC) power path management
    • System instant-on with depleted or no battery
    • Battery supplement when the adapter is fully loaded
  • Flexible autonomous or I2C-controlled modes
  • Integrated 12-bit ADC for voltage, current, and temperature monitoring
  • High Accuracy
    • ±0.4% charge voltage regulation
    • ±5% charge current regulation
    • ±5% input current regulation
  • Safety
    • Thermal regulation and thermal shutdown
    • Input, system, and battery overvoltage protection
    • Battery and converter overcurrent protection
    • Charging safety timer


  • Consumer wearables, smartwatch
  • Portable speakers, TWS earphones
  • Hearing aid or TWS charging case

Simplified Application

Texas Instruments bq25628E I2C Controlled Buck Battery Charger
Published: 2023-09-05 | Updated: 2023-09-12