SLUSF68 july   2023 BQ25173-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Device Power Up from Input Source
        1. 7.3.1.1 ISET Pin Detection
      2. 7.3.2 Supercapacitor Regulation Voltage
      3. 7.3.3 Supercapacitor Charging Profile
      4. 7.3.4 Status Outputs (PG, STAT)
        1. 7.3.4.1 Power Good Indicator (PG Pin)
        2. 7.3.4.2 Charging Status Indicator (STAT)
      5. 7.3.5 Protection Features
        1. 7.3.5.1 Input Overvoltage Protection (VIN OVP)
        2. 7.3.5.2 Output Overcurrent Protection (OUT OCP)
        3. 7.3.5.3 Thermal Regulation and Thermal Shutdown (TREG and TSHUT)
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown or Undervoltage Lockout (UVLO)
      2. 7.4.2 Sleep Mode
      3. 7.4.3 Active Mode
        1. 7.4.3.1 Standby Mode
      4. 7.4.4 Fault Mode
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 1s Supercapacitor Charger Design Example
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curves
      2. 8.2.2 4s Supercapacitor Charger Design Example
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Application Curves
  10. 9 Power Supply Recommendations
  11. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Thermal Considerations
  12. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.1 Overview

The BQ25173-Q1 is an automotive rated, 800-mA linear charger for 1- to 4-cell supercapacitors targeted at space-limited applications. The device has a single power output that charges the supercapacitor. The system load can be placed in parallel with the supercapacitor and the charge current is shared between the system and supercapacitor.

The charger is designed for a single path from the input to the output to charge the supercapacitor. Upon application of a valid input power source, the ISET pin is checked for short circuit.

The device attempts to charge the supercapacitor at the fast-charge current setting from fully discharged (0 V) up to the programmable regulation voltage, VREG. Power dissipation in the IC is greatest in fast charge with a lower supercapacitor voltage. If the IC temperature reaches TREG, the IC enters thermal regulation and reduces the charge current as needed to keep the temperature from rising any further. The fast-charge current is programmed using the ISET pin. Figure 7-1 shows the typical supercapacitor charging profile with thermal regulation. At lower fast-charge settings, the junction temperature of the IC is less than TREG and thermal regulation is not entered.

Once the supercapacitor has charged to the regulation voltage, the voltage loop takes control and holds the voltage at the regulation voltage as the current tapers down to zero. There is no current termination threshold as seen in Li-ion chargers.

Further details are described in Section 7.3.

GUID-CF2A937C-E2E2-4CFF-9C8B-0D5B24860A4C-low.pngFigure 7-1 Supercapacitor Charging Profile with Thermal Regulation