Part Number: UC1845A-EP
Hi All,
Customer is using UC1845A-EP and find an issue that Sense voltage on Pin3 will exceed 1V but the current limit function doesn't work. The schematic is as below.
There are two loops connect with Vfb, logic is as below. The issue happened load switch from no load to a inductance load, the control loop will switch from voltage loop to current loop, the inductor current will reach very high and make the transformer saturated.
So my question here is why the Isense current limit function failed during the voltage loop transits to current loop? Thanks.
Best Regards,
Vincent Zhang