TIDT283 May   2022

 

  1.   Description
  2.   Features
  3.   Applications
  4. 1Test Prerequisites
    1. 1.1 Voltage and Current Requirements
    2. 1.2 Required Equipment
    3. 1.3 Test Setup
  5. 2Testing and Results
    1. 2.1 UCC14240 Power-Up Sequence
    2. 2.2 UCC14240 Output Ripple
    3. 2.3 Gate Waveforms
    4. 2.4 Analog Sense
    5. 2.5 DESAT, OC
    6. 2.6 Thermal Images

2.5 DESAT, OC

This board implements overcurrent and short-circuit protection based on desaturation, as described in the Protection Based on Desaturation Circuit section of the UCC21732-Q1 data sheet. This implementation allows the detection voltage and blanking time to be set with external passive components, as described in the UCC217xx excel calculator tool. This feature is disabled by default on the board to allow testing with a capacitive load, but can be enabled by populating R1 with a 2.2-kΩ resistor and connecting TP14 to the drain of the power switch. The default DESAT voltage is 5.4 V, and the blanking time is 130 ns.