SLUSEG2C September   2022  – February 2024 BQ25620 , BQ25622

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Description (continued)
  6. 5 Device Comparison
  7. 6 Pin Configuration and Functions
  8. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Requirements
    7. 7.7 Typical Characteristics
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Power-On-Reset (POR)
      2. 8.3.2  Device Power Up from Battery
      3. 8.3.3  Device Power Up from Input Source
        1. 8.3.3.1 REGN LDO Power Up
        2. 8.3.3.2 Poor Source Qualification
        3. 8.3.3.3 D+/D– Detection Sets Input Current Limit (BQ25620 Only)
        4. 8.3.3.4 ILIM Pin (BQ25622 Only)
        5. 8.3.3.5 Input Voltage Limit Threshold Setting (VINDPM Threshold)
        6. 8.3.3.6 Converter Power-Up
      4. 8.3.4  Power Path Management
        1. 8.3.4.1 Narrow VDC Architecture
        2. 8.3.4.2 Dynamic Power Management
        3. 8.3.4.3 High Impedance Mode
      5. 8.3.5  Battery Charging Management
        1. 8.3.5.1 Autonomous Charging Cycle
        2. 8.3.5.2 Battery Charging Profile
        3. 8.3.5.3 Charging Termination
        4. 8.3.5.4 Thermistor Qualification
          1. 8.3.5.4.1 Advanced Temperature Profile in Charge Mode
          2. 8.3.5.4.2 TS Pin Thermistor Configuration
          3. 8.3.5.4.3 Cold/Hot Temperature Window in OTG Mode
          4. 8.3.5.4.4 JEITA Charge Rate Scaling
          5. 8.3.5.4.5 TS_BIAS Pin (BQ25622 Only)
        5. 8.3.5.5 Charging Safety Timers
      6. 8.3.6  USB On-The-Go (OTG)
        1. 8.3.6.1 Boost OTG Mode
      7. 8.3.7  Integrated 12-Bit ADC for Monitoring
      8. 8.3.8  Status Outputs ( PG, STAT, INT)
        1. 8.3.8.1 PG Pin Power Good Indicator
        2. 8.3.8.2 Interrupts and Status, Flag and Mask Bits
        3. 8.3.8.3 Charging Status Indicator (STAT)
        4. 8.3.8.4 Interrupt to Host ( INT)
      9. 8.3.9  BATFET Control
        1. 8.3.9.1 Shutdown Mode
        2. 8.3.9.2 Ship Mode
        3. 8.3.9.3 System Power Reset
      10. 8.3.10 Protections
        1. 8.3.10.1 Voltage and Current Monitoring in Battery Only and HIZ Modes
          1. 8.3.10.1.1 Battery Undervoltage Lockout
          2. 8.3.10.1.2 Battery Overcurrent Protection
        2. 8.3.10.2 Voltage and Current Monitoring in Buck Mode
          1. 8.3.10.2.1 Input Overvoltage
          2. 8.3.10.2.2 System Overvoltage Protection (SYSOVP)
          3. 8.3.10.2.3 Forward Converter Cycle-by-Cycle Current Limit
          4. 8.3.10.2.4 System Short
          5. 8.3.10.2.5 Battery Overvoltage Protection (BATOVP)
          6. 8.3.10.2.6 Sleep and Poor Source Comparators
        3. 8.3.10.3 Voltage and Current Monitoring in Boost Mode
          1. 8.3.10.3.1 Boost Mode Overvoltage Protection
          2. 8.3.10.3.2 Boost Mode Duty Cycle Protection
          3. 8.3.10.3.3 Boost Mode PMID Undervoltage Protection
          4. 8.3.10.3.4 Boost Mode Battery Undervoltage
          5. 8.3.10.3.5 Boost Converter Cycle-by-Cycle Current Limit
          6. 8.3.10.3.6 Boost Mode SYS Short
        4. 8.3.10.4 Thermal Regulation and Thermal Shutdown
          1. 8.3.10.4.1 Thermal Protection in Buck Mode
          2. 8.3.10.4.2 Thermal Protection in Boost Mode
          3. 8.3.10.4.3 Thermal Protection in Battery-Only Mode
    4. 8.4 Device Functional Modes
      1. 8.4.1 Host Mode and Default Mode
      2. 8.4.2 Register Bit Reset
    5. 8.5 Programming
      1. 8.5.1 Serial Interface
        1. 8.5.1.1 Data Validity
        2. 8.5.1.2 START and STOP Conditions
        3. 8.5.1.3 Byte Format
        4. 8.5.1.4 Acknowledge (ACK) and Not Acknowledge (NACK)
        5. 8.5.1.5 Target Address and Data Direction Bit
        6. 8.5.1.6 Single Write and Read
        7. 8.5.1.7 Multi-Write and Multi-Read
    6. 8.6 Register Maps
      1. 8.6.1 Register Programming
      2. 8.6.2 BQ25620 Registers
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Inductor Selection
        2. 9.2.2.2 Input Capacitor
        3. 9.2.2.3 Output Capacitor
      3. 9.2.3 Application Curves
  11. 10Power Supply Recommendations
  12. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  13. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Support Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  14. 13Revision History
  15. 14Mechanical, Packaging, and Orderable Information

Package Options

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

8.4.1 Host Mode and Default Mode

The device is a host controlled charger, but it can operate in default mode without host management. In default mode, the device can be used as an autonomous charger with no host or while host is in sleep mode. When the charger is in default mode, WD_STAT bit becomes HIGH, WD_FLAG is set to 1, and an INT is asserted low to alert the host (unless masked by WD_MASK). The WD_FLAG bit would read as 1 upon the first read and then 0 upon subsequent reads. When the charger is in host mode, WD_STAT bit is LOW.

After power-on-reset, the device starts in default mode with watchdog timer expired. All the registers are in the default settings.

In default mode, the device keeps charging the battery with default 1-hour trickle charging safety timer, 2-hour pre-charging safety timer and the 12-hour fast charging safety timer. At the end of the 1-hour or 2-hour or 12-hour timer expired, the charging is stopped and the buck converter continues to operate to supply system load.

A write to any I2C register transitions the charger from default mode to host mode, and initiates the watchdog timer. All the device parameters can be programmed by the host. To keep the device in host mode, the host has to reset the watchdog timer by writing 1 to WD_RST bit before the watchdog timer expires (WD_STAT bit is set), or disable watchdog timer by setting WATCHDOG bits = 00.

When the watchdog expires, the device returns to default mode. The ICHG value is divided in half when the watchdog timer expires, and a number of other fields are reset to their POR default values as shown in the notes column of the register tables in Section 8.6. When watchdog timer expires, WD_STAT and WD_FLAG is set to 1, and an INT is asserted low to alert the host (unless masked by WD_MASK).

GUID-1CEF2E4E-9657-457C-962E-49C07BA8C33D-low.gif Figure 8-8 Watchdog Timer Flow Chart