SLUSE31A April   2020  – February 2021 BQ25968

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
    6. 8.6 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  Charging System
      2. 9.3.2  Battery Charging Profile
      3. 9.3.3  Control State Diagram for System Implementation
      4. 9.3.4  Device Power Up
      5. 9.3.5  Switched Cap Function
        1. 9.3.5.1 Theory of Operation
      6. 9.3.6  Charging Start-Up
      7. 9.3.7  Integrated 16-Bit ADC for Monitoring and Smart Adapter Feedback
      8. 9.3.8  Device Internal Thermal Shutdown, TSBUS, and TSBAT Temperature Monitoring
      9. 9.3.9  INT Pin, STAT, FLAG, and MASK Registers
      10. 9.3.10 CDRVH and CDRVL_ADDRMS Functions
      11. 9.3.11 Parallel Operation Using Master and Slave Modes
    4. 9.4 Device Functional Modes
      1. 9.4.1 Device Modes and Protection Status
        1. 9.4.1.1 Input Overvoltage, Overcurrent, Undercurrent and Short-Circuit Protection
        2. 9.4.1.2 Battery Overvoltage and Overcurrent Protection
        3. 9.4.1.3 Cycle-by-Cycle Current Limit
    5. 9.5 Programming
      1. 9.5.1 F/S Mode Protocol
    6. 9.6 Register Maps
      1. 9.6.1 Customer Registers
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Standalone Application Information (for use with switching charger)
        1. 10.2.1.1 Design Requirements
        2. 10.2.1.2 Detailed Design Procedure
        3. 10.2.1.3 Application Curves
      2. 10.2.2 Parallel BQ25968 for Higher Power Applications
        1. 10.2.2.1 Design Requirements
        2. 10.2.2.2 Detailed Design Procedure
        3. 10.2.2.3 Application Curve
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Third-Party Products Disclaimer
      2. 13.1.2 Device Nomenclature
    2. 13.2 Documentation Support
      1. 13.2.1 Related Documentation
    3. 13.3 Receiving Notification of Documentation Updates
    4. 13.4 Support Resources
    5. 13.5 Trademarks
    6. 13.6 Electrostatic Discharge Caution
    7. 13.7 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

9.3.7 Integrated 16-Bit ADC for Monitoring and Smart Adapter Feedback

The integrated 16-bit ADC of the device allows the user to get critical system information for optimizing the behavior of the charger control. The control of the ADC is done through the ADC_CTRL register. The ADC_EN bit provides the ability to enable and disable the ADC to conserve power. The ADC_RATE bit allows continuous conversion or one-shot behavior. The ADC_AVG_DIS bit enbles or disables averaging

To enable the ADC, the ADC_EN bit must be set to ‘1’. The ADC is allowed to operate if either the VVBUS>VBUSPRESENT or VVOUT>VOUTPRESENT is valid. If ADC_EN is set to ‘1’ before VBUS or VOUT reach their respective PRESENT threshold, then the ADC conversion will be postponed until one of the power supplies reaches the threshold.

The ADC_SAMPLE bits control the sample speed of the ADC, with conversion times of tADC_CONV. The integrated ADC has two rate conversion options: a 1-Shot Mode and a Continuous Conversion Mode set by the ADC_RATE bit. By default, all ADC parameters will be converted in 1-Shot or Continuous Conversion Mode unless disabled in the ADC_FN_DIS register. If an ADC parameter is disabled by setting the correcsponding bit in the ADC_FN_DIS register, then the value in that register will be from the last valid ADC conversion or the default POR value (all zeros if no conversions have taken place). If an ADC parameter is disabled in the middle of an ADC measurement cycle, the device will finish the conversion of that parameter, but will not convert the parameter starting the next conversion cycle. Even though no conversion takes place when all ADC measurement parameters are disabled, the ADC circuitry is active and ready to begin conversion as soon as one of the bits in the ADC_FN_DIS register is set to ‘0’.

The ADC_DONE_* bits signal when a conversion is complete in 1-Shot Mode only. During Continuous Conversion Mode, the ADC_DONE_* bits have no meaning and will be ‘0’.

ADC conversion operates independently of the faults present in the device. ADC conversion will continue even after a fault has occurred (such as one that causes the power stage to be disabled), and the host must set ADC_EN = ‘0’ to disable the ADC. ADC readings are only valid for DC states and not for transients. When the host writes ADC_EN = ‘0’, the ADC stops immediately. If the host wants to exit ADC more gracefully, it is possible to do either of the following:

  1. Write ADC_RATE to one-shot, and the ADC will stop at the end of a complete cycle of conversions, or
  2. Write all the DIS bits low, and the ADC will stop at the end of the current measurement.