SLVUD40 November   2024 TPS25984B

 

  1.   1
  2.   TPS25984BEVM: Evaluation Module for TPS25984B eFuse
  3.   Trademarks
  4. 1Introduction
    1. 1.1 EVM Features
    2. 1.2 EVM Applications
  5. 2Description
  6. 3Schematic
  7. 4General Configurations
    1. 4.1 Physical Access
    2. 4.2 Test Equipment
      1. 4.2.1 Power Supplies
      2. 4.2.2 Meters
      3. 4.2.3 Oscilloscope
      4. 4.2.4 Loads
  8. 5Test Setup and Procedures
    1. 5.1  Hot Plug
    2. 5.2  Start-Up With Enable
    3. 5.3  Difference Between Current Limit and DVDT Based Start-Up Mechanisms
    4. 5.4  Power Up Into Short
    5. 5.5  Overvoltage Lockout
    6. 5.6  Transient Overload Performance
    7. 5.7  Overcurrent Event
    8. 5.8  Output Hot Short
    9. 5.9  Quick Output Discharge (QOD)
    10. 5.10 Thermal Performance of TPS25984BEVM
  9. 6EVAL Board Assembly Drawings and Layout Guidelines
    1. 6.1 PCB Drawings
  10. 7Bill of Materials (BOM)

5.8 Output Hot Short

Use the following instructions to perform the output hot short test:

  1. Set the input supply voltage VIN to 12V and connect the power supply between VIN (Connector T1) and PGND (Connector T3).
  2. Turn ON the power supply.
  3. Short the output of the device for example, VOUT (Connector T2) to PGND (Connector T3) through a shorter cable, which is just enough to insert a 150A current probe.
  4. Observe the waveforms using an oscilloscope.

Figure 5-13 shows the test waveforms of output hot short on the TPS25984BEVM with two (2) TPS25984B eFuses in parallel.

TPS25984BEVM Output Hot Short Response of TPS25984B eFuse
VIN = 12V, RILIM1 = 2kΩ, RILIM2 = 2kΩ, RIREF = 50kΩ, and COUT = 10µF
Figure 5-13 Output Hot Short Response of TPS25984B eFuse
Important: Make sure there is sufficient input capacitor to eliminate voltage dips at the input. A combination of electrolytic and ceramic capacitors are preferred. With these capacitors, a large current can be provided for a short period of time during short-circuit.
Note: Obtaining repeatable and similar short-circuit testing results is very difficult. The following contributes to the variation in results:
  • Source bypassing
  • Input leads
  • Board layout
  • Component selection
  • Output shorting method
  • Relative location of the short
  • Instrumentation

The actual short exhibits a certain degree of randomness because the short microscopically bounces and arcs. Make sure that configuration and methods are used to obtain realistic results. Hence, do not expect to see waveforms exactly like the waveforms in this user's guide because every setup is different.