Hello,
I am using the UCC28600 for a power supply with the following specs: 15-11VDC IN, Isolated 24VDC OUT @ 250mA. Please see the attachment below for a reference. The only changes I have made from the schematic is to short D434. The only reason I am using the UCC28600 in this application is because I am using it for the AC/DC converter on the same product and am trying to save $$ by not having to buy another controller.
The problem I am having is that I cannot get the circuit to operate in boost mode; my output is always ~2V less than my input. Even with no load attached, it uses alot of current, trying to hit 24V on the output but it just can't. When my input voltage exceeds 24V, the output stays at 24V, right on the dot.
I feel there is some fundamental flaw with my circuit that does not allow it to run in boost-mode. Almost every buck-boost isolated flyback circuit I see uses a split transformer, unlike mine. However, I did find one circuit that uses a standard transformer, only adding to the confusion. Can anybody help me out? If I need to provide more information just let me know.
