HOT -SWAP Design issue LTC4225-2

Hi Anoop,  It is not clear what is being hot swapped, which supply and whether it is the input or output. But, sounds like the supply to the CPU system is glitching or browning out. So work upstream from that point on to see what is turning off. You should probe the FET gates to see which one is turning off: DGATE turns off due to reverse current (i.e., output higher than input), while HGATE turns off due to current limiting action, EN#/ON pins, or INTVCC UVLO. For the FAULT# and PWRGD# pins, make sure not to exceed their 5mA absolute maximum rating. For further questions, please submit a Technical Support Request Form: https://form.analog.com/form_pages/support/integrated/techsupport.aspx

Hi Sachdev 

Thank you for replay, We designed the hot-swappable power supply card. It used in satellite communication MODEM, using two power supplies cards in one system, MODEM  will restart during Hot-swapping the 2nd power card. This card insertion time one spark sound from the output connector side.

The discharged C29, C30, C14, and C15 on the newly inserted 2nd power supply card may be sparking and pulling down the 5V and 3.3V on the backplane and the resident 1st power supply card.

Hi PSachdev 

Thanks a lot , we removed 4capacitor, problem solved.

Hi PSachdev 

Thanks a lot , we removed 4capacitor, problem solved.