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

8.3.6 Reverse Current Protection

The device monitors V(IN_SYS) and V(OUT) to provide true reverse current blocking when a reverse condition or input power failure condition is detected. The reverse comparator turns OFF the external blocking FET Q1 quickly as soon as V(IN_SYS) – V(OUT) falls below –1 V. The total time taken to turn OFF the FET Q1 in this condition is tRCB(fast_dly) + t(Driver). Use Equation 4 to calculate the delay due to the driver stage t(Driver).

Equation 4. TPS2663

where

  • RDSON(Q2) is the on resistance of the fast pulldown switch Q2
  • Ciss(Q1) is the input capacitance of the blocking FET Q1
  • VGTH(Q1) is the GATE threshold voltage of the blocking FET Q1
  • VBGATE = 10.2 V (typical)

In a typical system design, t(Driver) is generally 10% to 20% of tRCB(fast_dly) of 120 ns (typical).

Figure 8-10 and Figure 8-11 illustrate the behavior of the system during input hot short-circuit condition. The blocking FET Q1 is turned ON within 1.6 ms (typical) after the differential forward voltage V(IN_SYS) – V(OUT) exceeds 67 mV (typical).

TPS2663 Input Hot-Short Functionality at 24-V SupplyFigure 8-10 Input Hot-Short Functionality at 24-V Supply
TPS2663 Input Hot-Short: Fast-Trip Response (Zoomed)Figure 8-11 Input Hot-Short: Fast-Trip Response (Zoomed)

The reverse comparator architecture has a supply line noise immunity resulting in a robust performance in noisy environments. This event is achieved by controlling the turn-OFF time of the internal FET based on the over-drive differential voltage V(IN_SYS) – V(OUT) over V(REVTH). The higher the over-drive, the faster the turn-OFF time, tRCB(dly).