SLUSD04C july   2018  – april 2023 BQ25150

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Device Key Default Settings
  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 Timing Requirements
    7. 8.7 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  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
        6. 9.3.2.6 Maximum Allowable Charging Current (IMAX)
      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
  10. 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 IMAX Selection
        5. 10.2.2.5 Recommended Passive Components
      3. 10.2.3 Application Curves
  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. 13.2 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

9.3.2.6 Maximum Allowable Charging Current (IMAX)

The device allows the system designer to limit the maximum programmable charge current through hardware by connecting a resistor to the IMAX pin. The value of this resistor will determine the maximum Fast Charge I2C code that BQ25150 would let the host program to the device. Upon Power-On-Reset (POR) the ADC will measure the voltage at the IMAX pin, which is biased by a 80-µA biasing current. This measurement is used to determine the RIMAX value and the maximum charging current. Once the value is measured, the device determines the maximum allowable Fast Charge I2C code and prevents the host from programming any value higher than that. If the host tries to program it to a higher value, the IMAX_ACTIVE flag will be set and the Fast Charge Current Register will reflect the maximum charge current setting instead of the value programmed by the host. Note that even though the pre-charge current is also limited by IMAX if set higher than the IMAX value, the IMAX_ACTIVE flag is not set as it is only asserted for fast charge. Equation 6 shows the maximum ICHG_CTRL register value (decimal) for a given RIMAX.

Equation 6. GUID-4CDF6D50-9959-4BD7-8B6A-F5E91074A22F-low.gif

Note that the IMAX function has no effect on the charge current step size set by the ICHARGE_RANGE bit, so if RIMAX is selected based on the fast charge current when ICHARGE_RANGE = 0 (1.25-mA step), changing the ICHARGE_RANGE bit to 1 will double the maximum allowable current.In case where the IMAX pin is left floating (RIMAX > 14 KΩ,), the device will disable charging so that in the case the IMAX resistor connection is not done properly during manufacturing or breaks afterwards it prevents charging with a current above the desired IMAX level. If the measurement indicates that the IMAX pin is floating, the device repeats the measurement for a second time to confirm. If the floating pin measurement is confirmed then, charge is disabled permanently and the IMAX_FAULT flag is set. Note that a Power-On-Reset (POR) would be needed in order to repeat the IMAX measurement so both IN and BAT supplies must be removed before powering up the device again to update the IMAX state.