SLVSDX2A September   2017  – December 2017 TPS23521

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
    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 EMI Filter Consideration
        7. 9.2.2.7 Under Voltage and Over Voltage Settings
        8. 9.2.2.8 Choosing RVCC and CVCC
        9. 9.2.2.9 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

8.4.4 Normal Operation State

In this state the hot swap is fully on and the operation is set as follows:

  • The SS pin is disconnected from the GATE pin to improve transient response.
  • The full gate sourcing current is used to improve transient response.
  • The current limit and fast trip threshold are a function of the D pin to optimize the transient response while protecting the MOSFET.

If any of the following occur, the controller will be kicked back to the OFF state:

  • PG_degl goes low.
  • The timer times out due to over-current.
  • VCC is below its UVLO threshold and the IC doesn’t have enough power to operate properly.

Note that if the input voltage is outside the valid range or the fast trip is triggered, the hot swap FET will turn off, but the controller will not exit the Normal Operation state. In this case the PG signal would go low immediately. If this condition persists, the PG_degl will go low as well and the controller would move to the OFF state. This operation prevents the controller from re-starting the system during quick transients.