- Ask a related questionWhat is a related question?A related question is a question created from another question. When the related question is created, it will be automatically linked to the original question.
Hello,
During single point failure, component open short testing, shorting the below capacitor C25 causes the main switching MOSFET to catch fire.
The current sense signal is effectively shorted out, the inductor saturates, and then the MOSFET catches fire, which is a Safety failure.
At the bottom I pasted the UCC2818 block diagram.
What is a good fix for this that causes an orderly shut down, or some kind of low power or hiccup mode?
Here is the UCC2818 block diagram. Pins 4 and 5 are the current sense amp input
Below is the datasheet application circuit
Thanks.
Hi Jason,
Once you short C25, you will need rely on PKLIMIT to protect the main switch. Where is your current sense resistor? I am assuming it is below R32 and R33. In order to still have PKLIMIT signal when C25 is shorted, you will need to connect R26 to the negative side of the current sense resistor (the other end of R33), as shown in the datasheet.
Please let me know if this helps.
Regards,
Bosheng Sun
