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CSD95490Q5MC: About CSD95490Q5MC VSW TO PGND

Part Number: CSD95490Q5MC
Other Parts Discussed in Thread: TPS53679,


Our design is TPS53679+ CSD95490Q5MC (4+1) for Intel D-2100.

In CSD95490Q5MC datasheet Absolute Maximum Ratings has '' Vsw to Pgnd (10ns) ,min=-7v,max=23v".

Our design observes CSD95490Q5MC's Vsw is min=-5v,max=19v, BUT -5v is about 17ns.

Is it ok? Attached is our design.

  • Hi Wenxing,

    First we need to make sure the negative voltage is not caused by measurement noise.

    We suggest to use differential voltage probe to do the measurement, and place the probe as close as possible to power stage to minimize the parasitic inductance in the measurement loop. Usually we can get rid of most measurement noise in such way, and we are not expecting to see very high negative spike with optimized layout.

    If the negative spike was real with suggested measurement setup, which means we probably need to improve the board layout to reduce parasitic inductance.