SLVSEW6F August   2021  – March 2024 TPS7H2211-SEP , TPS7H2211-SP

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Options
  6. 5 Related Products
  7. 6 Pin Configuration and Functions
  8. 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: All Devices
    6. 7.6  Electrical Characteristics: CFP and KGD Options
    7. 7.7  Electrical Characteristics: HTSSOP Option
    8. 7.8  Switching Characteristics: All Devices
    9. 7.9  Quality Conformance Inspection
    10. 7.10 Typical Characteristics
  9. 8 Parameter Measurement Information
  10. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Enable and Overvoltage Protection
      2. 9.3.2 Current Limit
      3. 9.3.3 Soft Start (Adjustable Rise Time)
      4. 9.3.4 Parallel Operation
      5. 9.3.5 Reverse Current Protection
      6. 9.3.6 Forward Leakage Current
    4. 9.4 Device Functional Modes
  11. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Applications
      1. 10.2.1 Application 1: Cold Sparing
        1. 10.2.1.1 Design Requirements
        2. 10.2.1.2 Detailed Design Procedure
          1. 10.2.1.2.1 Capacitance
          2. 10.2.1.2.2 Enable Control
          3. 10.2.1.2.3 Overvoltage Protection
          4. 10.2.1.2.4 Soft Start Time
          5. 10.2.1.2.5 Summary
        3. 10.2.1.3 Application Curve
      2. 10.2.2 Application 2: Protection
        1. 10.2.2.1 Design Requirements
        2. 10.2.2.2 Detailed Design Procedure
          1. 10.2.2.2.1 Capacitance
          2. 10.2.2.2.2 Enable Control
          3. 10.2.2.2.3 Overvoltage Protection
          4. 10.2.2.2.4 Soft Start Time
          5. 10.2.2.2.5 Summary
        3. 10.2.2.3 Application Curve
    3. 10.3 Power Supply Recommendations
    4. 10.4 Layout
      1. 10.4.1 Layout Guidelines
      2. 10.4.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  13. 12Revision History
  14. 13Mechanical, Packaging, and Orderable Information

9.3.2 Current Limit

There is an internal current limit intended to protect the TPS7H2211 against hard short circuit conditions. Figure 9-4 shows a short circuit condition followed by an immediate recovery. The TPS7H2211 internal short circuit protection trips at IL_trip. It takes time tftr, for the internal circuitry to respond to the short circuit condition. Before the current limit circuitry responds, the current through the switch will continue to rise to a peak value, IL_peak. At this point the current limit circuitry responds and quickly turns off the switch. As there is no active discharge on VOUT, the rate of discharge will depend on external factors such as the short condition and COUT. The switch will stay off for time tfto, before turning-on again.

GUID-3E219286-4DE5-44FD-BB2A-D4DDF5B1E9BE-low.png
A. The following values were measured at VIN = 12 V, a parasitic switch inductance nominal value of 270 nH, and ROUT changing from 10 Ω to 10 mΩ in 1 μs:
  • IL_trip(typ) = 8.5 A
  • tftr(typ) = 2.3 μs
  • IL_peak(typ) = 25 A
  • tfto(typ) = 51 μs
Figure 9-4 Single Hard Short and Recovery

As shown in Figure 9-4, the TPS7H2211 is designed to quickly respond to a hard fault condition to minimize the current peak. IL_trip and tftr are highly dependent upon the actual fault conditions.

While Figure 9-4 shows a hard short condition that immediately recovers, Figure 9-5 shows a hard short condition that does not immediately recover. Instead, the device twice enters the fast trip mode before the fault is removed.

CAUTION: A short will repeat indefinitely until the short is removed or until the device is disabled. The TPS7H2211 is not intended to remain in this mode indefinitely.
GUID-0DAB2621-F090-45AA-998E-4AA696E14D0C-low.png Figure 9-5 Two Hard Shorts and Recovery