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

9.6.3 ChargeVoltage Register (I2C address = 05/04h) [reset value based on CELL_BATPRESZ pin setting]

To set the output charge voltage, write a 16-bit ChargeVoltage register command (REG0x05/04h()) using the data format listed in Figure 9-18, Table 9-12, and Table 9-13. The charger provides charge voltage range from 1.024 V to 23.000 V, with 8-mV step resolution. Any write below 1.024 V or above 23.000 V is ignored.

Upon POR, ChargeVoltage() is by default set as 4200 mV for 1 s, 8400 mV for 2 s, 12600 mV for 3 s or 16800 mV for 4 s, 21000 mV for 5s. After CHRG_OK goes high, the charge will start when the host writes the charging current to ChargeCurrent() register, the default charging voltage is used if ChargeVoltage() is not programmed. If the battery is different from 4.2 V/cell, the host has to write to ChargeVoltage() before ChargeCurrent() register for correct battery voltage setting. Writing ChargeVoltage() to 0 should keep ChargeVoltage() value unchanged, and force ChargeCurrent() register to zero to disable charge.

The SRN pin senses the battery voltage for voltage regulation and should be connected as close to the battery as possible.

Figure 9-18 ChargeVoltage Register (I2C address = 05/04h) [reset value based on CELL_BATPRESZ pin setting]
7 6 5 4 3 2 1 0
ReservedCharge Voltage, bit 11Charge Voltage, bit 10Charge Voltage, bit 9Charge Voltage, bit 8Charge Voltage, bit 7Charge Voltage, bit 6Charge Voltage, bit 5
R/WR/WR/WR/WR/WR/WR/WR/W
76543210
Charge Voltage, bit 4Charge Voltage, bit 3Charge Voltage, bit 2Charge Voltage, bit 1Charge Voltage, bit 0Reserved
R/WR/WR/WR/WR/WR/W
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 9-12 ChargeVoltage Register (I2C address = 05h) Field Descriptions
BITFIELDTYPERESETDESCRIPTION
7ReservedR/W0b

Not used. 1 = invalid write.

6Charge Voltage, bit 11R/W0b

0 = Adds 0 mV of charger voltage.

1 = Adds 16384 mV of charger voltage.

5Charge Voltage, bit 10R/W0b

0 = Adds 0 mV of charger voltage.

1 = Adds 8192 mV of charger voltage

4Charge Voltage, bit 9R/W0b

0 = Adds 0 mV of charger voltage.

1 = Adds 4096 mV of charger voltage.

3Charge Voltage, bit 8R/W0b

0 = Adds 0 mV of charger voltage.

1 = Adds 2048 mV of charger voltage.

2Charge Voltage, bit 7R/W0b

0 = Adds 0 mV of charger voltage.

1 = Adds 1024 mV of charger voltage.

1Charge Voltage, bit 6R/W0b

0 = Adds 0 mV of charger voltage.

1 = Adds 512 mV of charger voltage.

0Charge Voltage, bit 5R/W0b

0 = Adds 0 mV of charger voltage.

1 = Adds 256 mV of charger voltage.

Table 9-13 ChargeVoltage Register (I2C address = 04h) Field Descriptions
BITFIELDTYPERESETDESCRIPTION
7Charge Voltage, bit 4R/W0b

0 = Adds 0 mV of charger voltage.

1 = Adds 128 mV of charger voltage.

6Charge Voltage, bit 3R/W0b

0 = Adds 0 mV of charger voltage.

1 = Adds 64 mV of charger voltage.

5Charge Voltage, bit 2R/W0b

0 = Adds 0 mV of charger voltage.

1 = Adds 32 mV of charger voltage.

4Charge Voltage, bit 1R/W0b

0 = Adds 0 mV of charger voltage.

1 = Adds 16 mV of charger voltage.

3Charge Voltage, bit 0R/W0b

0 = Adds 0 mV of charger voltage.

1 = Adds 8 mV of charger voltage.

2-0ReservedR/W000bNot used. Value Ignored.