SLUSEC5A december   2020  – august 2023 BQ25157

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  MR Wake and Reset Input
        1. 9.3.7.1 MR Wake or Short Button Press Functions
        2. 9.3.7.2 MR Reset or Long Button Press Functions
      8. 9.3.8  14-Second Watchdog for HW Reset
      9. 9.3.9  Faults Conditions and Interrupts ( INT)
        1. 9.3.9.1 Flags and Fault Condition Response
      10. 9.3.10 Power Good ( PG) Pin
      11. 9.3.11 External NTC Monitoring (TS)
        1. 9.3.11.1 TS Thresholds
      12. 9.3.12 External NTC Monitoring (ADCIN)
      13. 9.3.13 I2C Interface
        1. 9.3.13.1 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

9.3.11 External NTC Monitoring (TS)

The I2C interface allows the user to easily implement the JEITA standard for systems where the battery pack thermistor is monitored by the host. Additionally, the device provides a flexible voltage based TS input for monitoring the battery pack NTC thermistor. The NTC thermistor is biased by the device with ITS_BIAS and the resulting voltage at TS is monitored to determine that the battery is at a safe temperature during charging. The TS pin is not biased continuously, instead it is biased only when the voltage at the pin is being sampled (for about 25ms in 225ms intervals when VIN is present. Note that the TS biasing cannot be disabled when VIN is present.

The part can be configured to meet JEITA requirements or a simpler HOT/COLD function only. Additionally, the TS charger control function can be disabled. To satisfy the JEITA requirements, four temperature thresholds are monitored: the cold battery threshold, the cool battery threshold, the warm battery threshold, and the hot battery threshold. These temperatures correspond to the VCOLD, VCOOL, VWARM, and VHOT thresholds in the Electrical Characteristics table. Charging and safety timers are suspended when VTS < VHOT or VTS > VCOLD. When VCOOL < VTS < VCOLD, the charging current is reduced to the value programmed in the TS_FASTCHGCTRL register. Note that the current steps for fast charge in the COOL region, just as those in normal fast charge, are multiples of the fast charge LSB value (1.25 mA by default). So in the case where the calculated scaled down current for the COOL region falls in between charge current steps, the device will round down the charge current to the nearest step. For example, if the fast charge current is set for 15 mA (ICHG = 1100) and TS_FASTCHARGE =111 (0.125*ICHG), the charge current in the COOL region will be 1.25 mA instead of the calculated 1.85 mA.

When VHOT < VTS < VWARM, the battery regulation voltage is reduced to the value programmed in the TS_FASTCHGCTRL register.

Regardless of whether the part is configured for JEITA, HOT/COLD, or disabled, when a TS fault occurs, a 128-µs pulse is sent on the INT output, and the FAULT bits of the register are updated over I2C. The FAULT bits are not cleared until they are read over I2C. This allows the host processor to take action if a different behavior than the pre-set function is needed. Alternately, the TS pin voltage can be read by the host if VIN is present or when BAT is present, so the appropriate action can be taken by the host.