Dear Experts,

I try to simulate PDN by lumped and distributed analysis with simple RLC and S-parameter model for the capacitor.

Please see the result in the picture below:

my Ztarget = 0.93 * 0.05 / (0.5 * 154) = 0.6mOhm.

Look into the result, I have some concerns below:

1 /. Why is there a big gap between blue line and red line? It mean which is more accuracy? simple RLC or S-parameter / SPICE model?

2 /. To tune PDN by changing the decoupling capacitor, which method simulation I should follow? Distributed or lumped analysis?

Thank you so much.

Ce message a été modifié par : Hung Dang

To answer your questions:

1 /. Why is there a big gap between the blue line and red line?

because the lumped RLC model does not match the impedance of the S-parameter model.It mean which is more accurate?

There is no way to know from this result. Accuracy depends on how well the model matches the real world. You have not shown the response of the real world.simple RLC or S-parameter / SPICE model?

2 /. To tune PDN by changing the decoupling capacitor, which method simulation I should follow? Distributed or lumped analysis?

The final analysis always needs to be distributed analysis. We use lumped analysis in the early stages of design because it runs much faster and is a good approximation.