Hi,
I know most of the application out there were for step down. However, for my case I'm interested in stepping up from a 12V input supply to around 48V output ~50W. I know that this should be doable with the change of configuration of the transformer's turn ratio.
What I'm curious was based on the datasheet mentioned in the PIN FUNCTIONS table, "If the power sources of VIN is outside of the range, LM5046 can be biased directly at VCC by an external regulator". I had tried that both within the PSpice model and the actual unit by sourcing 12V to VCC & VIN directly but no luck for me. For actual unit, it seems to sink a lot of current which tripped my external power supply. Based on the functional block diagram provided within datasheet, as long as VIN is no lower than VCC, it shouldn't biased the internal diode to sink so much current.
Any advice will be much appreciated.
thanks.