SLUSF18A October   2023  – December 2023 BQ25638

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Description (continued)
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Power-On-Reset (POR)
      2. 7.3.2  Device Power Up from Battery
      3. 7.3.3  Device Power Up from Input Source
        1. 7.3.3.1 REGN LDO Power Up
        2. 7.3.3.2 Poor Source Qualification
        3. 7.3.3.3 Input Voltage Limit Threshold Setting (VINDPM Threshold)
        4. 7.3.3.4 Converter Power-Up
        5. 7.3.3.5 Input Current Optimizer (ICO)
        6. 7.3.3.6 Switching Frequency and Dithering Feature
      4. 7.3.4  Power Path Management
        1. 7.3.4.1 Narrow VDC Architecture
        2. 7.3.4.2 Dynamic Power Management
          1. 7.3.4.2.1 Input Current Limit on ILIM Pin
        3. 7.3.4.3 High Impedance (HIZ) Mode
      5. 7.3.5  Battery Charging Management
        1. 7.3.5.1 Autonomous Charging Cycle
        2. 7.3.5.2 Battery Charging Profile
        3. 7.3.5.3 Charging Termination
        4. 7.3.5.4 Thermistor Qualification
          1. 7.3.5.4.1 Advanced Temperature Profile in Charge Mode
          2. 7.3.5.4.2 TS Pin Thermistor Configuration
          3. 7.3.5.4.3 Cold/Hot Temperature Window in OTG Mode
          4. 7.3.5.4.4 JEITA Charge Rate Scaling
          5. 7.3.5.4.5 TS_BIAS Pin
        5. 7.3.5.5 Charging Safety Timers
      6. 7.3.6  USB On-The-Go (OTG)
        1. 7.3.6.1 Boost OTG Mode
      7. 7.3.7  Integrated 12-bit ADC for Monitoring
      8. 7.3.8  Status Outputs (INT , PG , STAT)
        1. 7.3.8.1 PG Pin Power Good Indicator
        2. 7.3.8.2 Charging Status Indicator (STAT)
        3. 7.3.8.3 Interrupt to Host (INT)
      9. 7.3.9  BATFET Control
        1. 7.3.9.1 Shutdown Mode
        2. 7.3.9.2 Ultra-Low Power Mode
        3. 7.3.9.3 System Power Reset
      10. 7.3.10 Protections
        1. 7.3.10.1 Voltage and Current Monitoring in Battery Only and HIZ Modes
          1. 7.3.10.1.1 Battery Overcurrent Protection
          2. 7.3.10.1.2 Battery Undervoltage Lockout
        2. 7.3.10.2 Voltage and Current Monitoring in Forward Mode
          1. 7.3.10.2.1 Input Overvoltage
          2. 7.3.10.2.2 System Overvoltage Protection (SYSOVP)
          3. 7.3.10.2.3 Forward Converter Cycle-by-Cycle Current Limit
          4. 7.3.10.2.4 System Short
          5. 7.3.10.2.5 Battery Overvoltage Protection (BATOVP)
          6. 7.3.10.2.6 Sleep and Poor Source Comparators
        3. 7.3.10.3 Voltage and Current Monitoring in Reverse Mode
          1. 7.3.10.3.1 Boost Mode Overvoltage Protection
          2. 7.3.10.3.2 Boost Mode Duty Cycle Protection
          3. 7.3.10.3.3 Boost Mode PMID Undervoltage Protection
          4. 7.3.10.3.4 Boost Mode Battery Undervoltage
          5. 7.3.10.3.5 Boost Converter Cycle-by-Cycle Current Limit
          6. 7.3.10.3.6 Boost Mode SYS Short
        4. 7.3.10.4 Thermal Regulation and Thermal Shutdown
          1. 7.3.10.4.1 Thermal Protection in Buck Mode
          2. 7.3.10.4.2 Thermal Protection in Boost Mode
          3. 7.3.10.4.3 Thermal Protection in Battery-only Mode
    4. 7.4 Device Functional Modes
      1. 7.4.1 Host Mode and Default Mode
      2. 7.4.2 Register Bit Reset
    5. 7.5 Programming
      1. 7.5.1 Serial Interface
        1. 7.5.1.1 Data Validity
        2. 7.5.1.2 START and STOP Conditions
        3. 7.5.1.3 Byte Format
        4. 7.5.1.4 Acknowledge (ACK) and Not Acknowledge (NACK)
        5. 7.5.1.5 Target Address and Data Direction Bit
        6. 7.5.1.6 Single Write and Read
        7. 7.5.1.7 Multi-Write and Multi-Read
    6. 7.6 BQ25638 Registers
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Inductor Selection
        2. 8.2.2.2 Input Capacitor
        3. 8.2.2.3 Output Capacitor
      3. 8.2.3 Application Curves
  10. 9 Power Supply Recommendations
  11. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Support Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  13. 12Revision History
  14. 13Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • YBG|30
Thermal pad, mechanical data (Package|Pins)
Orderable Information

4 Description (continued)

The device supports a wide range of input sources, including standard USB host port, USB charging port, and USB compliant high voltage adapter. It is compliant with USB 2.0 and USB 3.0 power specifications for input current and voltage regulation. In addition, the Input Current Optimizer (ICO) supports the detection of maximum power point of the input source without overload. BQ25638 has an ILIM pin to set the default input current limit and a TS_BIAS pin for controlled thermistor bias. The device also meets USB On-the-Go (OTG) operation power rating specification with constant current limit up to 3.2 A.

The power path management regulates the system slightly above battery voltage but does not drop below the programmable minimum system voltage. With this feature, the system maintains operation even when the battery is completely depleted or removed. When the input current limit or input voltage limit is reached, the power path management automatically reduces the charge current. If the system load continues to increase, the power path discharges the battery until the system power requirement is met. This supplement mode prevents overloading the input source.

The device initiates and completes a charging cycle without host control. By sensing the battery voltage, it charges the battery in four different phases: trickle charge, pre-charge, constant current (CC) charge and constant voltage (CV) charge. At the end of the charging cycle, the charger automatically terminates when the charge current is below a preset threshold and the battery voltage is higher than the recharge threshold. Termination is supported for TS pin COOL, PRECOOL, NORMAL, WARM and PREWARM temperature zones. When the full battery voltage falls below the programmable recharge threshold, the charger automatically starts a new charging cycle.

The charger provides various safety features for battery charging and system operations, including battery negative temperature coefficient (NTC) thermistor monitoring, charging safety timer and overvoltage and overcurrent protections. The thermal regulation reduces charge current when the junction temperature exceeds the programmable threshold. The STAT output reports the charging status and any fault conditions. Other safety features include battery temperature sensing for charge mode and OTG boost mode, thermal shutdown and input UVLO and over-voltage protection. The PG output indicates if a good power source is present and above the programmable PG_TH value. The INT output immediately notifies the host when a fault occurs or status changes.

The device also provides a 12-bit analog-to-digital converter (ADC) for monitoring charge current and input/battery/system (VBUS, BAT, SYS, TS) voltages. In addition, the ADCIN pin can be used to monitor an external signal up-to 1V. The QON pin provides BATFET enable and reset control to exit ultra-low power mode or initiate a full system reset.

BQ25638 is available in a 30-ball, 2.0 mm × 2.4 mm DSBGA package.