Hello TI, my name is Genik.
I have a question regarding LM3478 PWM controller. After adding supply (3v or above to 8 pin), my controller starts with 100% duty cycle all the time. I tried connect pin 2 (COMP) to GND and duty cycle was near 10% all the time. I tried make boost converter from SEPIC but problem is the same. My data is next:
Vin=8 to 30Vdc
Vout=14.4Vdc
Iout=8A_max
All my calculations in attached PDF file.
One more question. I found mistake in formula 38 of AN-1484, in current sense gain. The example was written the number 91, and if you use the formula 1 / Rsn it will be 52, where is the truth? And may be better use LM3481 chip? it has duty cycle limit 85%.Genik_SEPIC.pdf
