SLVSE94G September   2018  – June 2024

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 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 Timing Requirements
    7. 6.7 Typical Characteristics
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Hot Plug-In and Inrush Current Control
        1. 8.3.1.1 Thermal Regulation Loop
      2. 8.3.2  PGOOD and PGTH
        1. 8.3.2.1 PGTH as VOUT Sensing Input
      3. 8.3.3  Undervoltage Lockout (UVLO)
      4. 8.3.4  Overvoltage Protection (OVP)
      5. 8.3.5  Input Reverse Polarity Protection (B_GATE, DRV)
      6. 8.3.6  Reverse Current Protection
      7. 8.3.7  Overload and Short-Circuit Protection
        1. 8.3.7.1 Overload Protection
          1. 8.3.7.1.1 Active Current Limiting at 1 × IOL (TPS26630 and TPS26632 Only)
          2. 8.3.7.1.2 Active Current Limiting With 2 × IOL Pulse Current Support (TPS26631, TPS26633, TPS26635, TPS26636, and TPS26637 Only)
        2. 8.3.7.2 Short-Circuit Protection
          1. 8.3.7.2.1 Start-Up With Short Circuit on Output
      8. 8.3.8  Output Power Limiting, PLIM (TPS26632, TPS26633, TPS26635, TPS26636, and TPS26637 Only)
      9. 8.3.9  Current Monitoring Output (IMON)
      10. 8.3.10 FAULT Response (FLT)
      11. 8.3.11 IN_SYS, IN, OUT, and GND Pins
      12. 8.3.12 Thermal Shutdown
      13. 8.3.13 Low Current Shutdown Control (SHDN)
    4. 8.4 Device Functional Modes
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application: Power Path Protection in a PLC System
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Programming the Current-Limit Threshold—R(ILIM) Selection
        2. 9.2.2.2 Undervoltage Lockout and Overvoltage Set Point
        3. 9.2.2.3 Output Buffer Capacitor – COUT
        4. 9.2.2.4 PGTH Set Point
        5. 9.2.2.5 Setting Output Voltage Ramp Time—(tdVdT)
          1. 9.2.2.5.1 Support Component Selections— RPGOOD and C(IN)
        6. 9.2.2.6 Selecting Q1, Q2 and TVS Clamp for Surge Protection
      3. 9.2.3 Application Curves
    3. 9.3 System Examples
      1. 9.3.1 Simple 24-V Power Supply Path Protection
      2. 9.3.2 Priority Power MUX Operation
      3. 9.3.3 Input Protection for a Compact 24-V Auxiliary Power Supply for Servo Drives
    4. 9.4 Dos and Do Nots
    5. 9.5 Power Supply Recommendations
      1. 9.5.1 Transient Protection
    6. 9.6 Layout
      1. 9.6.1 Layout Guidelines
      2. 9.6.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

9.2.2.3 Output Buffer Capacitor – COUT

During the power interruption time TFAIL_TR the output capacitor COUT of the TPS26630 provides energy to the 15 W DC-DC converter load. Use Equation 11 to compute the required buffer capacitor COUT

Equation 11. TPS2663

where

  • P(DC-DC) = 15 W/η. Assuming efficiency of 95%, P(DC-DC) = 15.8 W
  • TFAIL_TR = 10 ms
  • V(IN_SYS) = 24 V
  • V(UV_DC-DC) = 15 V

COUT = 0.9 mF. Choose a capacitor with ±10% tolerance, COUT = 1 mF/35 V electrolytic capacitor. Figure 9-4 and Figure 9-5 illustrate the performance during the power interruption tests on TPS26630. Figure 9-8 illustrates the performance on TPS26631.