SLVSDF9A December   2017  – January 2019 TPS23523

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 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 Switching Characteristics
    7. 6.7 Typical Characteristics
  7. 7 Parameter Measurement Information
    1. 7.1 Relationship between Sense Voltage, Gate Current, and Timer
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Current Limit
        1. 8.3.1.1 Programming the CL Switch-Over Threshold
        2. 8.3.1.2 Setting Up the PROG Pin
        3. 8.3.1.3 Programming CL1
        4. 8.3.1.4 Programming CL2
      2. 8.3.2 Soft Start Disconnect
      3. 8.3.3 Timer
      4. 8.3.4 Gate 2
      5. 8.3.5 OR-ing
    4. 8.4 Device Functional Modes
      1. 8.4.1 OFF State
      2. 8.4.2 Insertion Delay State
      3. 8.4.3 Start-up State
      4. 8.4.4 Normal Operation State
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1  Selecting RSNS
        2. 9.2.2.2  Selecting Soft Start Setting: CSS and CSS,VEE
        3. 9.2.2.3  Selecting VDS Switch Over Threshold
        4. 9.2.2.4  Timer Selection
        5. 9.2.2.5  MOSFET Selection and SOA Checks
        6. 9.2.2.6  Input Cap, Input TVS, and OR-ing FET selection
        7. 9.2.2.7  EMI Filter Consideration
        8. 9.2.2.8  Undervoltage and Overvoltage Settings
        9. 9.2.2.9  Choosing RVCC and CVCC
        10. 9.2.2.10 Power Good Interface to Downstream DC/DC
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Community Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.5 OR-ing

The TPS23523 features integrated OR-ing that controls the external MOSFET in a way to emulate an ideal diode. The TPS23523 will regulate the forward drop across the OR-ing FET to 25 mV. This is accomplished by controlling the VGS of the MOSFET. As the current decreases the VGS is also decreased, which effectively increases the RDSON of the MOSFET. This process is regulated with a low gain amplifier that is gate (OR-ing FET) pole compensated. The lower gain helps ensure stability over various operating conditions. The regulating amplifier ensures that there is no DC reverse current.

However, the amplifier is not very fast and thus it is paired with a fast comparator. This comparator quickly turns off the FET if there is significant reverse current detected.

TPS23523 TPS23523_ORing_BD.pngFigure 12. Simplified Diagram of OR-ing Block