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TPS53219a: Spike on TPS53219A+CSD87330Q3D output at the first application of power

Part Number: TPS53219A
Other Parts Discussed in Thread: CSD87330Q3D,

AC input: 19V supply

DC output 3.3V standby

circuit: TPS53219A + CSD87330Q3D with 1uH/18A/3m inductor and 2x330uF POSCAP's.

When the board is in off state, the 3.3V standby will always be ON. I found that when the power supply is hot plugged, there is a momentary high spike on 3.3V output (goes upto 8 or 9V for < 100us) and then it turns off momentarily. I don't see this spike using a bench top supply or using a power strip on/off button. My colleague however sees the spike with the power strip on/off but not with a bench top supply. I don't see this spike on the 19V line but I see it on all the sub power rails in the off state at the time of the first application of 19V power.

I have the same circuit on another board except the dc jack is on the chassis and is connected to the board via an adapter cable. I do not see this spike on this board with the same test conditions. What could be the cause for this spike and how can I solve it ? 

Thanks,

Lakshmi