SLUSE66A June   2020  – January 2021 BQ25731

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Device Comparison Table
  7. 7 Pin Configuration and Functions
  8. 8 Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics(BQ25731)
    6. 8.6 Timing Requirements
    7. 8.7 Typical Characteristics
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1  Power-Up Sequence
      2. 9.3.2  Two-Level Battery Discharge Current Limit
      3. 9.3.3  Fast Role Swap Feature
      4. 9.3.4  CHRG_OK Indicator
      5. 9.3.5  Input and Charge Current Sensing
      6. 9.3.6  Input Voltage and Current Limit Setup
      7. 9.3.7  Battery Cell Configuration
      8. 9.3.8  Device HIZ State
      9. 9.3.9  USB On-The-Go (OTG)
      10. 9.3.10 Converter Operation
      11. 9.3.11 Inductance Detection Through IADPT Pin
      12. 9.3.12 Converter Compensation
      13. 9.3.13 Continuous Conduction Mode (CCM)
      14. 9.3.14 Pulse Frequency Modulation (PFM)
      15. 9.3.15 Switching Frequency and Dithering Feature
      16. 9.3.16 Current and Power Monitor
        1. 9.3.16.1 High-Accuracy Current Sense Amplifier (IADPT and IBAT)
        2. 9.3.16.2 High-Accuracy Power Sense Amplifier (PSYS)
      17. 9.3.17 Input Source Dynamic Power Management
      18. 9.3.18 Input Current Optimizer (ICO)
      19. 9.3.19 Two-Level Adapter Current Limit (Peak Power Mode)
      20. 9.3.20 Processor Hot Indication
        1. 9.3.20.1 PROCHOT During Low Power Mode
        2. 9.3.20.2 PROCHOT Status
      21. 9.3.21 Device Protection
        1. 9.3.21.1 Watchdog Timer
        2. 9.3.21.2 Input Overvoltage Protection (ACOV)
        3. 9.3.21.3 Input Overcurrent Protection (ACOC)
        4. 9.3.21.4 System Overvoltage Protection (SYSOVP)
        5. 9.3.21.5 Battery Overvoltage Protection (BATOVP)
        6. 9.3.21.6 Battery Discharge Overcurrent Protection (BATOC)
        7. 9.3.21.7 Battery Short Protection (BATSP)
        8. 9.3.21.8 System Undervoltage Lockout (VSYS_UVP)
        9. 9.3.21.9 Thermal Shutdown (TSHUT)
    4. 9.4 Device Functional Modes
      1. 9.4.1 Forward Mode
      2. 9.4.2 USB On-The-Go
      3. 9.4.3 Pass Through Mode (PTM)-Patented Technology
    5. 9.5 Programming
      1. 9.5.1 I2C Serial Interface
        1. 9.5.1.1 Timing Diagrams
        2. 9.5.1.2 Data Validity
        3. 9.5.1.3 START and STOP Conditions
        4. 9.5.1.4 Byte Format
        5. 9.5.1.5 Acknowledge (ACK) and Not Acknowledge (NACK)
        6. 9.5.1.6 Target Address and Data Direction Bit
        7. 9.5.1.7 Single Read and Write
        8. 9.5.1.8 Multi-Read and Multi-Write
        9. 9.5.1.9 Write 2-Byte I2C Commands
    6. 9.6 Register Map
      1. 9.6.1  ChargeOption0 Register (I2C address = 01/00h) [reset = E70Eh]
      2. 9.6.2  ChargeCurrent Register (I2C address = 03/02h) [reset = 0080h]
        1. 9.6.2.1 Battery Low Voltage Current Clamp
      3. 9.6.3  ChargeVoltage Register (I2C address = 05/04h) [reset value based on CELL_BATPRESZ pin setting]
      4. 9.6.4  ChargerStatus Register (I2C address = 21/20h) [reset = 0000h]
      5. 9.6.5  ProchotStatus Register (I2C address = 23/22h) [reset = B800h]
      6. 9.6.6  IIN_DPM Register (I2C address = 25/24h) [reset = 4100h]
      7. 9.6.7  ADCVBUS/PSYS Register (I2C address = 27/26h)
      8. 9.6.8  ADCIBAT Register (I2C address = 29/28h)
      9. 9.6.9  ADCIIN/CMPIN Register (I2C address = 2B/2Ah)
      10. 9.6.10 ADCVSYS/VBAT Register (I2C address = 2D/2Ch)
      11. 9.6.11 ChargeOption1 Register (I2C address = 31/30h) [reset = 3F00h]
      12. 9.6.12 ChargeOption2 Register (I2C address = 33/32h) [reset = 00B7]
      13. 9.6.13 ChargeOption3 Register (I2C address = 35/34h) [reset = 0434h]
      14. 9.6.14 ProchotOption0 Register (I2C address = 37/36h) [reset = 4A81h(2S~5s) 4A09(1S)]
      15. 9.6.15 ProchotOption1 Register (I2C address = 39/38h) [reset = 41A0h]
      16. 9.6.16 ADCOption Register (I2C address = 3B/3Ah) [reset = 2000h]
      17. 9.6.17 ChargeOption4 Register (I2C address = 3D/3Ch) [reset = 0048h]
      18. 9.6.18 Vmin Active Protection Register (I2C address = 3F/3Eh) [reset = 006Ch(2s~5s)/0004h(1S)]
      19. 9.6.19 OTGVoltage Register (I2C address = 07/06h) [reset = 09C4h]
      20. 9.6.20 OTGCurrent Register (I2C address = 09/08h) [reset = 3C00h]
      21. 9.6.21 InputVoltage(VINDPM) Register (I2C address = 0B/0Ah) [reset =VBUS-1.28V]
      22. 9.6.22 IIN_HOST Register (I2C address = 0F/0Eh) [reset = 2000h]
      23. 9.6.23 ID Registers
        1. 9.6.23.1 ManufactureID Register (I2C address = 2Eh) [reset = 40h]
        2. 9.6.23.2 Device ID (DeviceAddress) Register (I2C address = 2Fh) [reset = D6h]
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Input Snubber and Filter for Voltage Spike Damping
        2. 10.2.2.2 ACP-ACN Input Filter
        3. 10.2.2.3 Inductor Selection
        4. 10.2.2.4 Input Capacitor
        5. 10.2.2.5 Output Capacitor
        6. 10.2.2.6 Power MOSFETs Selection
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
      1. 12.2.1 Layout Example Reference Top View
      2. 12.2.2 Inner Layer Layout and Routing Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Third-Party Products Disclaimer
    2. 13.2 Documentation Support
      1. 13.2.1 Related Documentation
    3. 13.3 Support Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

3 Description

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.

Device Information
PART NUMBER PACKAGE(1) BODY SIZE (NOM)
BQ25731 WQFN (32) 4.00 mm × 4.00 mm
(1) For all available packages, see the orderable addendum at the end of the data sheet.
Application Diagram