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UC3845A: Does UC3845A have OC protection when start-up?

Part Number: UC3845A

Hi Team,

I am wondering UC3845A have overcurrent protection in start-up. If yes, how to accomplish. Thanks.

Best Regards.


  • Hi Wiky,

    Peak current mode control protects against OCP on a cycle-by-cycle basis. If the load is in OCP during start up, and you are starting from a high-voltage VIN, then the bias winding supplying VCC will not be able to regulate and the controller may be stuck in "start-stop(OCP)-retry" mode until the OCP condition is removed or VIN or the PWM controller is disabled. If the output load is high but not at the OCP level, the bias winding will come up and the output will be OCP protected as it would normally be during steady state. Thanks for connecting through E2E and good luck with your design.


    Steve M