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

9.3.1 Linear Charger and Power Path

The BQ25155 IC integrates a linear charger that allows the battery to be charged with a programmable charge current of up to 500 mA. In addition to the charge current, other charging parameters can be programmed through I2C such as the battery regulation voltage, pre-charge current, termination current, and input current limit current.

The power path allows the system to be powered from PMID, even when the battery is dead or charging, by drawing power from IN pin. It also prioritizes the system load connected to PMID, reducing the charging current, if necessary, in order to support the load when input power is limited. If the input supply is removed and the battery voltage level is above VBATUVLO, PMID will automatically and seamlessly switch to battery power.

There are several control loops that influence the charge current: constant current loop (CC), constant voltage loop (CV), input current limit, VDPPM, and VINDPM. During the charging process, all loops are enabled and the one that is dominant takes control regulating the charge current as needed. The charger input has back to back blocking FETs to prevent reverse current flow from PMID to IN. They also integrate control circuitry regulating the input current and prevents excessive currents from being drawn from the IN power supply for more reliable operation.

The device supports multiple battery regulation voltage regulation settings (VBATREG) and charge current (ICHARGE) options to support multiple battery chemistries for single-cell applications.

A more detailed description of the charger functionality is presented in the following sections of this document.