SLUSDO1B june   2019  – august 2023 BQ25155

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Description (continued)
  7. 6 Device Key Default Settings
  8. 7 Pin Configuration and Functions
  9. 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 Timing Requirements
    7. 8.7 Typical Characteristics
  10. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1  Linear Charger and Power Path
        1. 9.3.1.1 Battery Charging Process
          1. 9.3.1.1.1 Pre-Charge
          2. 9.3.1.1.2 Fast Charge
          3. 9.3.1.1.3 Pre-Charge to Fast Charge Transitions and Charge Current Ramping
          4. 9.3.1.1.4 Termination
        2. 9.3.1.2 JEITA and Battery Temperature Dependent Charging
        3. 9.3.1.3 Input Voltage Based Dynamic Power Management (VINDPM) and Dynamic Power Path Management (DPPM)
        4. 9.3.1.4 Battery Supplement Mode
      2. 9.3.2  Protection Mechanisms
        1. 9.3.2.1 Input Over-Voltage Protection
        2. 9.3.2.2 Safety Timer and I2C Watchdog Timer
        3. 9.3.2.3 Thermal Protection and Thermal Charge Current Foldback
        4. 9.3.2.4 Battery Short and Over Current Protection
        5. 9.3.2.5 PMID Short Circuit
      3. 9.3.3  ADC
        1. 9.3.3.1 ADC Operation in Active Battery Mode and Low Power Mode
        2. 9.3.3.2 ADC Operation When VIN Present
        3. 9.3.3.3 ADC Measurements
        4. 9.3.3.4 ADC Programmable Comparators
      4. 9.3.4  VDD LDO
      5. 9.3.5  Load Switch/LDO Output and Control
      6. 9.3.6  PMID Power Control
      7. 9.3.7  System Voltage (PMID) Regulation
      8. 9.3.8  MR Wake and Reset Input
        1. 9.3.8.1 MR Wake or Short Button Press Functions
        2. 9.3.8.2 MR Reset or Long Button Press Functions
      9. 9.3.9  14-Second Watchdog for HW Reset
      10. 9.3.10 Faults Conditions and Interrupts ( INT)
        1. 9.3.10.1 Flags and Fault Condition Response
      11. 9.3.11 Power Good ( PG) Pin
      12. 9.3.12 External NTC Monitoring (TS)
        1. 9.3.12.1 TS Thresholds
      13. 9.3.13 External NTC Monitoring (ADCIN)
      14. 9.3.14 I2C Interface
        1. 9.3.14.1 F/S Mode Protocol
    4. 9.4 Device Functional Modes
      1. 9.4.1 Ship Mode
      2. 9.4.2 Low Power
      3. 9.4.3 Active Battery
      4. 9.4.4 Charger/Adapter Mode
      5. 9.4.5 Power-Up/Down Sequencing
    5. 9.5 Register Map
      1. 9.5.1 I2C Registers
  11. 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 (IN/PMID) Capacitors
        2. 10.2.2.2 VDD, LDO Input and Output Capacitors
        3. 10.2.2.3 TS
        4. 10.2.2.4 Recommended Passive Components
      3. 10.2.3 Application Curves
  12. 11Power Supply Recommendations
  13. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  14. 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 Receiving Notification of Documentation Updates
    4. 13.4 Support Resources
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Trademarks
    7. 13.7 Glossary
  15. 14Mechanical, Packaging, and Orderable Information

Package Options

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

9.3.2.2 Safety Timer and I2C Watchdog Timer

At the beginning of the charge cycle, the device starts the safety timer. If charging has not terminated before the programmed safety time, tMAXCHG, expires, charging is disabled. The pre-charge safety time, tPRECHG, is 25% of tMAXCHG. When a safety timer fault occurs, a single 128-µs pulse is sent on the INT pin and the SAFETY_TMR_FAULT_FLAG bit in the FLAG3 register is updated over I2C. The CE pin or input power must be toggled in order to reset the safety timer and exit the fault condition. Note that the flag bit will be reset when the bit is read by the host even if the fault has not been cleared. The safety timer duration is programmable using the SAFETY_TIMER bits. When the safety timer is active, changing the safety timer duration resets the safety timer. The device also contains a 2X_TIMER bit that doubles the timer duration in order to prevent premature safety timer expiration when the charge current is reduced by a high load on PMID (DPPM operation), VIN DPM, thermal regulation, or a NTC (JEITA) condition. When 2X_TIMER function is enabled, the timer is allowed to run at half speed when any loop is active other than CC or CV.

In addition to the safety timer, the device contains a 50-second I2C watchdog timer that monitors the host through the I2C interface. The watchdog timer is enabled by default and may be disabled by the host through I2C. Once the watchdog timer is enabled, the watchdog timer is started. The watchdog timer is reset by any transaction by the host using the I2C interface. If the watchdog timer expires without a reset from the I2C interface, all charger parameters registers (ICHARGE, IPRECHARGE, ITERM,VLOWV, etc.) are reset to the default values.