SLVSFQ6A November   2020  – June 2021 TPS2640

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison
  6. 6 Pin Configuration and Functions
  7. 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 Timing Requirements
    7. 7.7 Typical Characteristics
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Undervoltage Lockout (UVLO)
      2. 9.3.2 Overvoltage Protection (OVP)
      3. 9.3.3 Reverse Input Supply Protection
      4. 9.3.4 Hot Plug-In and In-Rush Current Control
      5. 9.3.5 Overload and Short Circuit Protection
        1. 9.3.5.1 Overload Protection
          1. 9.3.5.1.1 Active Current Limiting
          2. 9.3.5.1.2 Electronic Circuit Breaker with Overload Timeout, MODE = OPEN
        2. 9.3.5.2 Short Circuit Protection
          1. 9.3.5.2.1 Start-Up With Short-Circuit On Output
        3. 9.3.5.3 FAULT Response
          1. 9.3.5.3.1 Look Ahead Overload Current Fault Indicator
        4. 9.3.5.4 Current Monitoring
        5. 9.3.5.5 IN, OUT, RTN, and GND Pins
        6. 9.3.5.6 Thermal Shutdown
        7. 9.3.5.7 Low Current Shutdown Control (SHDN)
    4. 9.4 Device Functional Modes
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Step by Step Design Procedure
        2. 10.2.2.2 Undervoltage Lockout and Overvoltage Set Point
        3. 10.2.2.3 Programming Current Monitoring Resistor—RIMON
        4. 10.2.2.4 Setting Output Voltage Ramp Time—(tdVdT)
          1. 10.2.2.4.1 Case 1: Start-Up Without Load—Only Output Capacitance C(OUT) Draws Current During Start-Up
          2. 10.2.2.4.2 Case 2: Start-Up With Load—Output Capacitance C(OUT) and Load Draws Current During Start-Up
          3. 10.2.2.4.3 Support Component Selections—RFLTb and C(IN)
      3. 10.2.3 Application Curves
    3. 10.3 System Examples
      1. 10.3.1 Acive ORing Operation
      2. 10.3.2 Field Supply Protection in PLC, DCS I/O Modules
      3. 10.3.3 Simple 24-V Power Supply Path Protection
    4. 10.4 Do's and Dont's
  11. 11Power Supply Recommendations
    1. 11.1 Transient Protection
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
    2. 13.2 Documentation Support
      1. 13.2.1 Related Documentation
    3. 13.3 Receiving Notification of Documentation Updates
    4. 13.4 Support Resources
    5. 13.5 Trademarks
    6. 13.6 Electrostatic Discharge Caution
    7. 13.7 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

9.3.5.2 Short Circuit Protection

During a transient output short circuit event, the current through the device increases very rapidly. As the currentlimit amplifier cannot respond quickly to this event due to its limited bandwidth, the device incorporates a fast-trip comparator, with a threshold I(FASTRIP). The fast-trip comparator turns off the internal FET within 250 ns (typical), when the current through the FET exceeds I(FASTRIP) (I(OUT) > I(FASTRIP)), and terminates the rapid short-circuit peak current. The fast-trip threshold is internally set to 87% higher than the programmed overload current limit (I(FASTRIP) = 1.87 × I(OL) + 0.015). The fast-trip circuit holds the internal FET off for only a few microseconds, after which the device turns back on slowly, allowing the current-limit loop to regulate the output current to I(OL). Then, device behaves similar to overload condition. Figure 9-12 and Figure 9-13 illustrate the behavior of the system when the current exceeds the fast-trip threshold.

GUID-20200603-SS0I-51BT-HVSH-CVHJXJMRXKW3-low.png

VIN = 24 V, RILIM = 5.36 kΩ

Figure 9-12 Output Hot Short Functionality at 24-V Input
GUID-20200603-SS0I-VBHK-G96D-N0VJLPKFDWVJ-low.pngFigure 9-13 Zoomed at the Instance of Output Short