SLUSBZ9C August 2015  – September 2016 BQ25120 , BQ25121


  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Description (continued)
  6. Device Comparison Table
  7. Pin Configuration and Functions
  8. Specifications
    1. 8.1Absolute Maximum Ratings
    2. 8.2ESD Ratings
    3. 8.3Recommended Operating Conditions
    4. 8.4Thermal Information
    5. 8.5Electrical Characteristics
    6. 8.6Timing Requirements
    7. 8.7Typical Characteristics
  9. Detailed Description
    1. 9.1Overview
    2. 9.2Functional Block Diagram
    3. 9.3Feature Description
      1. 9.3.1 Ship Mode
      2. 9.3.2 High Impedance Mode
      3. 9.3.3 Active Battery Only Connected
      4. 9.3.4 Voltage Based Battery Monitor
      5. 9.3.5 Sleep Mode
      6. 9.3.6 Input Voltage Based Dynamic Power Management (VIN(DPM))
      7. 9.3.7 Input Overvoltage Protection and Undervoltage Status Indication
      8. 9.3.8 Battery Charging Process and Charge Profile
      9. 9.3.9 Dynamic Power Path Management Mode
      10. 9.3.10Battery Supplement Mode
      11. 9.3.11Default Mode
      12. 9.3.12Termination and Pre-Charge Current Programming by External Components (IPRETERM)
      13. 9.3.13Input Current Limit Programming by External Components (ILIM)
      14. 9.3.14Charge Current Programming by External Components (ISET)
      15. 9.3.15Safety Timer and Watchdog Timer
      16. 9.3.16External NTC Monitoring (TS)
      17. 9.3.17Thermal Protection
      18. 9.3.18Typical Application Power Dissipation
      19. 9.3.19Status Indicators (PG and INT)
      20. 9.3.20Chip Disable (CD)
      21. 9.3.21Buck (PWM) Output
      22. 9.3.22Load Switch / LDO Output and Control
      23. 9.3.23Manual Reset Timer and Reset Output (MR and RESET)
    4. 9.4Device Functional Modes
    5. 9.5Programming
      1. 9.5.1Serial Interface Description
      2. 9.5.2F/S Mode Protocol
    6. 9.6Register Maps
      1. 9.6.1 Status and Ship Mode Control Register
      2. 9.6.2 Faults and Faults Mask Register
      3. 9.6.3 TS Control and Faults Masks Register
      4. 9.6.4 Fast Charge Control Register
      5. 9.6.5 Termination/Pre-Charge and I2C Address Register
      6. 9.6.6 Battery Voltage Control Register
      7. 9.6.7 SYS VOUT Control Register
      8. 9.6.8 Load Switch and LDO Control Register
      9. 9.6.9 Push-button Control Register
      10. 9.6.10ILIM and Battery UVLO Control Register
      11. 9.6.11Voltage Based Battery Monitor Register
      12. 9.6.12VIN_DPM and Timers Register
  10. 10Application and Implementation
    1. 10.1Application Information
    2. 10.2Typical Application
      1. 10.2.1Design Requirements
      2. 10.2.2Detailed Design Procedure
        1. Settings
        2. the Correct Inductance and Capacitance
          1. the Fast Charge Current (ISET)
          2. the Input Current Limit (ILIM)
          3. the Pre-charge/termination Threshold (IPRETERM)
          4. Resistors (TS)
      3. 10.2.3Application Performance Curves
        1. Curves
        2. Output Curves
        3. Switch and LDO Curves
        4. Output Curves
        5. Waveforms Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1Layout Guidelines
    2. 12.2Layout Example
  13. 13Device and Documentation Support
    1. 13.1Device Support
      1. 13.1.1Third-Party Products Disclaimer
    2. 13.2Related Links
    3. 13.3Receiving Notification of Documentation Updates
    4. 13.4Community Resources
    5. 13.5Trademarks
    6. 13.6Electrostatic Discharge Caution
    7. 13.7Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Orderable Information

1 Features

  • Increases System Operation Time Between Charges
    • Configurable 300-mA Buck Regulator
      (1.8-V Default)
    • 700 nA (typical) Iq with Buck Converter Enabled (No Load)
    • Configurable Load Switch or 100mA LDO Output (Load Switch by Default)
    • Up to 300-mA Charge Current for Fast Charging
    • 0.5% Accurate Battery Voltage Regulation (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
  • Highly Integrated Solution with Small Footprint
    • 2.5 mm x 2.5 mm WCSP Package and 6 External Components for Minimal Solution
    • Push-Button Wake-Up and Reset with Adjustable Timers
    • Power Path Management for Powering the System and Charging the Battery
    • Power Path Management enables <50 nA Ship Mode Battery Quiescent Current for Longest Shelf Life
    • Battery Charger Operates from 3.4 V – 5.5 VIN (5.5-V OVP / 20-V Tolerant)
    • 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
    • VINDPM Threshold
    • Timer Options
    • Load Switch Control
    • Controls for Interrupts for Faults and Status
    • System Output Voltage Adjustment
    • LDO Output Voltage Adjustment

2 Applications

  • Smart Watches and other Wearable Devices
  • Fitness Accessories
  • Health Monitoring Medical Accessories
  • Rechargeable Toys

3 Description

The bq2512x is a highly integrated battery charge management IC that integrates the most common functions for wearable devices: Linear charger, regulated output, load switch, manual reset with timer, and 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 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.

Device Information(1)

BQ2512xDSBGA (25)2.50 mm x 2.50 mm
  1. For all available packages, see the orderable addendum at the end of the datasheet.

Simplified Schematic

BQ25120 BQ25121 simple_schematic_slusbz9.gif

4 Revision History

Changes from B Revision (May 2016) to C Revision

Changes from A Revision (August 2015) to B Revision

  • Added BQ25121 device to data sheet Go
  • Added BQ25121 device to BATTERY-PACK NTC MONITOR specs in the Electrical Characteristics tableGo
  • Changed Figure 1 Go
  • Added Figure 14 typical characteristics graph Go
  • Changed text From: '.... current out of ISET is 1/400 (±10%)...." To: " ...current out of ISET is 1/100 (±10%)..." in Charge Current Programming by External Components (ISET) section.Go
  • Added sentence “This bit is for testing and debug only and not intended to be used in the final system." to the Buck (PWM) Output for clarification of the EN_SYS_OUT bit description.Go
  • Added text to Bit B3 Description in Table 14 Go

Changes from * Revision (August 2015) to A Revision

  • Changed From: Product Preview To: Production data Go