Hello,
I am currently investigating LM51551-Q1 for an application.
When studying Application Note SNVA866 I was wondering about Diode D3.
You are writing this is an design with attempted operation in CCM. Therefore I would assume D3 is used as freewheeling path for the transformer current during (1-D)T. This would mean it needs to be able to carry the max. average current of IL. during (1-D)T.
With calculation above, I would assume:
I_D,av=(Pout,tot)/(V_sup,min*d)*(1-d)=20,2W/(18V*0,357)*0,643=2 A
You selected a 1 Amp Diode. ES1C-13-F
Is this current rating still sufficient? Did make any false assumptions about the operation of LM51551-Q1?
Would be very grateful for any help!
Thank you very much!
