SLUSAH0G october   2011  – august 2023 BQ25504

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Description (continued)
  7. 6 Pin Configuration and Functions
  8. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Typical Characteristics
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Maximum Power Point Tracking
      2. 8.3.2 Battery Undervoltage Protection
      3. 8.3.3 Battery Overvoltage Protection
      4. 8.3.4 Battery Voltage in Operating Range (VBAT_OK Output)
      5. 8.3.5 Nano-Power Management and Efficiency
    4. 8.4 Device Functional Modes
      1. 8.4.1 Cold-Start Operation (VSTOR < VSTOR_CHGEN, VIN_DC > VIN(CS) and PIN > PIN(CS))
      2. 8.4.2 Main Boost Charger Enabled (VSTOR > VSTOR_CHGEN, VIN_DC > VIN(DC) and EN = LOW )
      3. 8.4.3 Thermal Shutdown
  10. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Storage Element Selection
      2. 9.1.2 Inductor Selection
      3. 9.1.3 Capacitor Selection
        1. 9.1.3.1 VREF_SAMP Capacitance
        2. 9.1.3.2 VIN_DC Capacitance
        3. 9.1.3.3 VSTOR Capacitance
        4. 9.1.3.4 Additional Capacitance on VSTOR or VBAT
    2. 9.2 Typical Applications
      1. 9.2.1 Solar Application Circuit
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curves
      2. 9.2.2 TEG Application Circuit
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
        3. 9.2.2.3 Application Curves
      3. 9.2.3 MPPT Disabled, Low Impedance Source Application Circuit
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Detailed Design Procedure
        3. 9.2.3.3 Application Curves
  11. 10Power Supply Recommendations
  12. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 Thermal Considerations
  13. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
      2. 12.1.2 Zip Files
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Support Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  14. 13Mechanical, Packaging, and Orderable Information

Package Options

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

9.2.3.2 Detailed Design Procedure

The recommended L1 = 22 µH, CBYP = 0.01 µF and low leakage CREF = 10 nF are selected. The minimum recommended CIN = 4.7 µF is selected. To prevent VSTOR from drooping during system load transients, CSTOR is set to 100 µF. To disable the sampling for MPPT, the VOC_SAMP pin is tied to VSTOR. To disable the input voltage regulation circuit, the VREF_SAMP pin is tied to GND. Since the VBAT_UV function is not needed, the VBAT_UV can be tied to VSTOR. To stop charging when the IC junction temperature is above 65°C, the OT_PROG pin is tied to GND.

Referring back to the procedure in Section 9.2.1.2 or using the spreadsheet calculator at SLURAQ1 gives the following values:

  • ROV1 = 5.62 MΩ, ROV2 = 4.22 MΩ resulting in VBAT_OV = 3.28 V due to rounding to the nearest 1% resistor.
  • ROK1 = 4.12 MΩ, ROK2 = 5.11 MΩ, ROK3 = 0.976 MΩ resulting in VBAT_OK = 2.80 V and VBAT_OK_HYST = 3.10 V after rounding.