Hi,
I have used UC38086 pwm controller to design a pushpull conveter. While doing the short circuit test, the ic is not going to hiccup mode and input power is taking on output short circuit. Can you suggest a soultion?
Regards,
Aswathy
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Hi,
I have used UC38086 pwm controller to design a pushpull conveter. While doing the short circuit test, the ic is not going to hiccup mode and input power is taking on output short circuit. Can you suggest a soultion?
Regards,
Aswathy
Aswathy,
Thanks for connecting through E2E. It is an excellent forum for Engineers to learn from each other and it works best when problems and recommended solutions are stated as clearly as possible. TI appreciates and values every thread entry into E2E but yours needs more information to benefit yourself and others who visit E2E. Your question can only be answered with more questions:
Regards,
Steve M
Hi Steve,
Please see comments below
I have tried tuning, Rsense, RC of CS pin, Iset pin resistor & CTRL pin resistor, output inductor. Then, also IC is not going to hiccup mode on short circuit. Do you have any suggestions on these values? Which is the most critical Item among these, to make the short circuit work?
Hi Steve,
Please see comments below
I have tried tuning, Rsense, RC of CS pin, Iset pin resistor & CTRL pin resistor, output inductor. Then, also IC is not going to hiccup mode on short circuit. Do you have any suggestions on these values? Which is the most critical Item among these, to make the short circuit work?
Aswathy,
You have not provided any waveforms, so I can only make "best guesses" what might be happening? It sounds like the current is folding back into a power limit. If you are referring to "hiccup mode" as try/retry after a number of counted clock cycles, I don't believe UCC38086 has this feature? Please see attached for help.
Regards,
Steve
Steve,
Thanks for the reply. You meant to say, UCC38086 doesn't have hiccup feature? So, how will the output short circuit work, for this particular IC? In our circuit, when output is shorted, the circuit is constantly taking 40W power from input. How can we limit or eliminate this?
Aswathy,
You need to determine what the design will tolerate during short circuit withstand and implement the best corrective action.
Steve