Hi
I use the LM5576 in a non isolated Buck Design 54V to 5V / 2A (Peak 4A), In as many as 10 converters I found similar failure pattern. LM5576 fails along with free wheel diode V12P10 shorts. Some logic ICs and sensors also fails which are connected to 5V. In logic ICs similar failure observed - VCC pin shorted to Ground. Can someone give answer to following questions
1. Logic ICs fails because of over voltage on 5V ? which leads to LM5576 and diode failure ?
2. How over voltage generated on 5V ?
3. Over voltage generated because of non isolated converter ?
4. How free wheel diode shorts despite adequate rating 12A / 100V ?
5. LM5576 fails because of short circuit on 5V ? short circuit current is 4.2A.
Best Regards
Kaushik Patel