The issue about the PD55008-E

bobber · ‎2025-10-12

Hi,i meeting a issue,

I suspect that the parasitic capacitance from the PD55008-E is too large?

The waveform output from J500 and the edge is shaking too much.

Thanks!

bobber · ‎2025-10-12

Are there any other options? For example, replacement plan...

Peter BENSCH · ‎2025-10-13

So far, apart from the schematic extract, you have only mentioned a few marginal parameters and no layout details.

The ringing observed at 15MHz when switching off (?) can be caused, for example, by line inductance in addition to L501 together with the parallel capacitors C507 and C506.

What do you mean by ‘replacement plan’?

Regards
/Peter

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bobber · ‎2025-10-14

Hi Peter,

The first,thank you for your support.

I understand what you mean now.

This is Layout picture:

The signal frequency is 40 MHz output from J500,but I'm pretty sure I won't be able to modify the layout.

The 'replacement plan' is replace PD55008-E with a smaller parasitic capacitance MOSFET.

Thanks

Best reagrds

Xingqi