BQ25125 Battery Charge Management Solution

Texas Instruments' low-IQ highly-integrated solution is ideal for applications such as wearables and IoT

Texas Instruments' BQ25125 Battery Charge Management SolutionTexas Instruments' BQ25125 is a highly-integrated battery charge management IC that integrates very common functions for wearable devices including a linear charger, a regulated output, a load switch, a manual reset with a timer, and a battery voltage monitor. The integrated buck converter is a high-efficiency, low-IQ switcher using DCS control™ that extends light-load efficiency down to 10 µA load currents.

The low quiescent current during operation and shutdown enables maximum battery life. The BQ25125 device supports charge currents from 5 mA to 300 mA. The input current limit, charge current, buck converter output voltage, LDO output voltage, and other parameters are programmable through the I2C interface.

The battery is charged using a standard Li-Ion charge profile with three phases including precharge, constant current, and constant voltage. A voltage-based JEITA-compatible battery pack thermistor monitoring input (TS) is included to monitor the battery temperature and to automatically change the charge parameters preventing the battery from charging outside of its safe temperature range. The charger is optimized for a 5 V USB input, with 20 V tolerance to withstand line transients. The buck converter is run from the input or the battery. When it is in battery-only mode, the device can run from a battery up to 4.65 V.

A configurable load switch allows for system optimization by disconnecting infrequently used devices. The manual reset with a timer allows multiple configuration options for wake are reset optimization. A simple voltage-based monitor provides battery-level information to the host in 2% increments from 60% to 100% of the programmed V(BATREG).

  • Increases system operation time between charges:
    • Configurable 300 mA buck regulator (1.8 V default)
    • 700 nA (typ.) IQ with the buck converter enabled (no-load)
    • Configurable load switch or 100 mA LDO output (1.8 V default)
    • Up to 300 mA charge-current for fast charging
    • Accurate battery voltage regulation: 0.5% (configurable from 3.6 V to 4.65 V in 10 mV steps)
    • Configurable termination current: down to 500 µA
    • Simple voltage-based battery monitor
    • Watchdog timer enabled by default
    • VDPPM loop disabled
    • VINDPM disabled by default to support low-voltage charging
  • Small footprint: 2.5 mm x 2.5 mm WCSP package
  • Power-path management enables <50 nA ship-mode battery quiescent current for ultra-long shelf life
  • Battery charger operates from 3.4 VIN to 5.5 VIN (5.5 VOVP/20 V tolerant)
  • Six external components for a minimal solution
  • Pushbutton wake-up and reset with adjustable timers
  • Power-path management for powering the system and charging the battery
  • Dedicated pins for input current limit, charge current, termination current, and status output
  • I2C communication control:
    • Charge voltage and current
    • Termination threshold
    • Input current limit
    • VIN(DPM) threshold
    • Timer options
    • Load switch control
    • Interrupt controls for faults and status
    • System output voltage adjustment
    • LDO output voltage adjustment
  • Smart watches and other wearable devices
  • Fitness accessories
  • Health monitoring medical accessories
  • Rechargeable toys
  • True wireless headsets (TWS)
  • Wirelessly charged products

BQ25125 Battery Charge Management Solution

ImageManufacturer Part NumberDescriptionNumber of CellsCurrent - ChargingProgrammable FeaturesAvailable QuantityView Details

Evaluation Boards

ImageManufacturer Part NumberDescriptionTypeFunctionAvailable QuantityView Details
BQ25120AEVMBQ25120AEVMBQ25120AEVMPower ManagementBattery Charger2 - Immediate
19 - Factory Stock
View Details
EVAL MODULE INTERFACE BOARDEV2400EVAL MODULE INTERFACE BOARDInterfaceUSB 2.0 to SMBus Bridge2874 - Factory StockView Details
Published: 2019-08-08