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UCC256403: UCC25640X Overcurrent protection or circuit protection

Part Number: UCC256403

hi Team:

I want to use UCC256403/404  designed  ac-dc POWER, when the output Over current protection or short circuit protection, I don't need  to auto-recover,and I need to latch(Re-energize the input voltage, it recover output ),Is that possible?

  • Hi David,

    Thanks for reaching out. It is possible to realize latching protection functions using external circuits. Here is an example for latching OVP

    When Vout rises high enough for the zeners to conduct, current is driven through the opto-coupler and turns on the NPN. The NPN pulls the base of the PNP low, turning on the PNP. This further biases the NPN and keeps the NPN on and pull BLK low. The circuit silicon controlled rectifier will remain on until VCC is recycled. A similar circuit can be used for OCP by using a current sense amplifier fed to a comparator whose output is connected to the anode opto-coupler. When the comparator output goes high, the opto-coupler will engage the SCR and latch off the LLC converter.

    For reference, take a look at this article by Robert Kollman about using SCR for latching protection circuits:

    Best Regards,

    Ben Lough