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

9.1 Application Information

The TPS23523 is a hot swap controller for –48-V applications and is used to manage inrush current and protect downstream circuitry and the upstream bus in case of fault conditions. The following key scenarios should be considered when designing a –48-V hot swap circuit:

  • Start Up.
  • Output of a hot swap is shorted to ground while the hot swap is on. This is often referred to as a Hot Short.
  • Powering up a board when the output and ground are shorted. This is usually called a start-into-short.
  • Input lightning surge. Here it is usually desired to avoid damage to downstream circuitry and to avoid system restarts.

These scenarios place a lot of stress on the hot swap MOSFET and the board designer should take special care to ensure that the MOSFET stays within it's Safe Operating Area (SOA) under all of these conditions. A detailed design example is provided below and the key equations are written out. Note that solving all of these equations by hand is cumbersome and can result in errors. Instead, TI recommends using the TPS2352X Design Calculator provided on the product page.