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
9.3.5.1.1 Active Current Limiting

When the active current limiting mode is selected, during overload events, the device continuously regulates the load current to the overcurrent limit I(OL) programmed by the R(ILIM) resistor as shown in Equation 3.

Equation 3. GUID-20200603-SS0I-VHVL-SNGK-QXNZLDMZQ051-low.gif

where

  • I(OL) is the overload current limit in Ampere
  • R(ILIM) is the current limit resistor in kΩ

During an overload condition, the internal current-limit amplifier regulates the output current to I(LIM). The FLT signal assert after a delay of 875 μs. The output voltage droops during the current regulation, resulting in increased power dissipation in the device. If the device junction temperature reaches the thermal shutdown threshold (T(TSD)), the internal FET is turn off. The device configured in latch-off mode stays latched off until it is reset by either of the following conditions:

  • Cycling V(IN) below V(PORF)
  • Toggling SHDN

Whereas the device configured in auto-retry mode, commences an auto-retry cycle 512 ms after TJ < [T(TSD) – 10°C]. The FLT signal remains asserted until the fault condition is removed and the device resumes normal operation. Figure 9-8 and Figure 9-9 illustrates behavior of the system during current limiting with auto-retry functionality.

GUID-20200603-SS0I-NLLC-WJ0W-X2WX9SHSDR3R-low.png

Load transition from 22 Ω to 12 Ω MODE pin connected to RTN RILIM = 8 kΩ

Figure 9-8 Auto-Retry MODE Fault Behavior
GUID-20200603-SS0I-MKT8-BQM9-FMB9BTPLWJ9Z-low.png

RILIM = 5.36 kΩ

Figure 9-9 Response During Coming Out of Overload Fault