SLUSEN5A August   2023  – August 2026 BQ25756

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Requirements
    7. 5.7 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1  Device Power-On-Reset
      2. 6.3.2  Device Power-Up From Battery Without Input Source
      3. 6.3.3  Device Power Up from Input Source
        1. 6.3.3.1 VAC Operating Window Programming (ACUV and ACOV)
        2. 6.3.3.2 REGN Regulator (REGN LDO)
        3. 6.3.3.3 Compensation-Free Buck-Boost Converter Operation
        4. 6.3.3.4 Light-Load Operation
        5. 6.3.3.5 Switching Frequency and Synchronization (FSW_SYNC)
        6. 6.3.3.6 Device HIZ Mode
      4. 6.3.4  Battery Charging Management
        1. 6.3.4.1 Autonomous Charging Cycle
          1. 6.3.4.1.1 Charge Current Programming (ICHG pin and ICHG_REG)
        2. 6.3.4.2 Li-Ion Battery Charging Profile
        3. 6.3.4.3 LiFePO4 Battery Charging Profile
        4. 6.3.4.4 Charging Termination for Li-ion and LiFePO4
        5. 6.3.4.5 Charging Safety Timer
        6. 6.3.4.6 Thermistor Qualification
          1. 6.3.4.6.1 JEITA Guideline Compliance in Charge Mode
          2. 6.3.4.6.2 Cold/Hot Temperature Window in Reverse Mode
      5. 6.3.5  Power Management
        1. 6.3.5.1 Dynamic Power Management: Input Voltage and Input Current Regulation
          1. 6.3.5.1.1 Input Current Regulation
            1. 6.3.5.1.1.1 ILIM_HIZ Pin
          2. 6.3.5.1.2 Input Voltage Regulation
            1. 6.3.5.1.2.1 Max Power Point Tracking (MPPT) for Solar PV Panel
      6. 6.3.6  Reverse Mode Power Direction
      7. 6.3.7  Integrated 16-Bit ADC for Monitoring
      8. 6.3.8  Status Outputs (PG, STAT1, STAT2, and INT)
        1. 6.3.8.1 Power Good Indicator (PG)
        2. 6.3.8.2 Charging Status Indicator (STAT1, STAT2 Pins)
        3. 6.3.8.3 Interrupt to Host (INT)
      9. 6.3.9  Protections
        1. 6.3.9.1 Voltage and Current Monitoring
          1. 6.3.9.1.1 VAC Over-voltage Protection (VAC_OVP)
          2. 6.3.9.1.2 VAC Under-voltage Protection (VAC_UVP)
          3. 6.3.9.1.3 Battery Over-voltage Protection (BAT_OVP)
          4. 6.3.9.1.4 Battery Over-current Protection (BAT_OCP)
          5. 6.3.9.1.5 Reverse Mode Over-voltage Protection (REV_OVP)
          6. 6.3.9.1.6 Reverse Mode Under-voltage Protection (REV_UVP)
          7. 6.3.9.1.7 DRV_SUP Under-voltage and Over-voltage Protection (DRV_OKZ)
          8. 6.3.9.1.8 REGN Under-voltage Protection (REGN_OKZ)
        2. 6.3.9.2 Thermal Shutdown (TSHUT)
      10. 6.3.10 Serial Interface
        1. 6.3.10.1 Data Validity
        2. 6.3.10.2 START and STOP Conditions
        3. 6.3.10.3 Byte Format
        4. 6.3.10.4 Acknowledge (ACK) and Not Acknowledge (NACK)
        5. 6.3.10.5 Target Address and Data Direction Bit
        6. 6.3.10.6 Single Write and Read
        7. 6.3.10.7 Multi-Write and Multi-Read
    4. 6.4 Device Functional Modes
      1. 6.4.1 Host Mode and Default Mode
      2. 6.4.2 Register Bit Reset
    5. 6.5 BQ25756 Registers
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Applications
      1. 7.2.1 Typical Application
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
          1. 7.2.1.2.1 ACUV / ACOV Input Voltage Operating Window Programming
          2. 7.2.1.2.2 Charge Voltage Selection
          3. 7.2.1.2.3 Switching Frequency Selection
          4. 7.2.1.2.4 Inductor Selection
          5. 7.2.1.2.5 Input (VAC) Capacitor
          6. 7.2.1.2.6 Output (VBAT) Capacitor
          7. 7.2.1.2.7 Sense Resistor (RAC_SNS and R BAT_SNS ) and Current Programming
          8. 7.2.1.2.8 Power MOSFETs Selection
          9. 7.2.1.2.9 Converter Fast Transient Response
        3. 7.2.1.3 Application Curves
      2. 7.2.2 Typical Application (USB-PD EPR Configuration)
        1. 7.2.2.1 Design Requirements
  9. 8 Power Supply Recommendations
  10. 9 Layout
    1. 9.1 Layout Guidelines
    2. 9.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Third-Party Products Disclaimer
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information
6.3.5.1.1 Input Current Regulation

The total input current is a function of the system supply current and the battery charging current. System current normally fluctuates as portions of the systems are powered up or down. Without DPM, the source must be able to supply the maximum system current and the maximum charger input current simultaneously. By using DPM, the battery charger reduces the charging current when the input current exceeds the input current limit set by the lower of IAC_DPM register bits, or ILIM_HIZ pin. This allows the current capability of the input source to be lowered, reducing system cost.

There are two thresholds to limit the input current (if both are enabled, the lower limit of these two will apply):

  1. IAC_DPM register bits (host software control)
  2. ILIM_HIZ pull down resistor (hardware control)

The default IAC_DPM is set to maximum code, allowing ILIM_HIZ pin to limit the current in hardware.

To set the maximum current using the ILIM_HIZ pin, refer to Section 6.3.5.1.1.1.

For example, using a 5mΩ resistor yields programmability from 400mA to 20A with 50mA/step.