Inrush current in ceramic capacitor too high?

[grizedale]

Hello,

We are seeing 25 Amps of inrush current in a 4u7, 100V, X7S, 1210 ceramic capacitor at switch-on.
(25 Amps pulse lasts for 10us)

Is this too high?

Capacitor is C3225X7S2A475K
Page 90 of this.....
**broken link removed**

The circuit is a coupled inductor SEPIC SMPS , and the ceramic capacitor here is used as the SEPIC capacitor.
Vin = 10V
Vout = 48V, 350mA
SEPIC inductor = 33uH (each coil when other open)

 

[jpanhalt]

A ceramic capacitor will have a pretty low ESR. You can use this calculator to estimate Imax and time from the datasheet ESR.

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capchg.html

John

 

[FvM]

I wonder how do you get the current value? In a simulation with zero leakage inductance?

Apart from question if 25A is real, I assume that capacitor won't have problems to accept the pulse of this short duration, because the total energy is still in a µWs order of magnitude.