Short term overvoltage on ceramic capacitor will damage it?

Hello,
During the startup inrush event, the voltage on our 630V, 220nF ceramic capacitor goes up to 800V as in the attached waveform.
Will this damage the capacitor?

(schematic and ltspice simulation also attached)

The capacitor datasheet is here…
https://datasheets.avx.com/HV-FlexitermMLCC.pdf

This thread discussed this but didn’t give conclusion.
https://www.edaboard.com/showthread.php?t=320810

Good practice for Derating the ceramic capacitor is 70% of its rated voltage with Case temperature = 10C less than its Tmax and surface temperature shall not increase more than 20°C.. As worst case, 85% shall be derated.

As per LT spice model, the V at C9 & C10 is ~600V. The max rated voltage is 630V and 70% of rated voltage is 441V (Allowed voltage). Worst case (85%) is 535.5V. There is possibility of failure on normal case.

The capacitor is over stressed (>630V) about 1ms.

1. Abnormal voltages (surge voltage, static electricity, pulse voltage, etc.) shall not exceed the rated voltage and If it is applied, it may cause dielectric breakdown and result in a short circuit.
2. General capacitors are designed for DC use. When they are used in a circuit, where AC or pulse voltage is applied, the current value may increase and the capacitors may short-circuited due to self-heating.

Suggested to use 1000V rated capacitor.

The capacitor is over stressed (>630V) about 1ms.

Click to expand...

Thanks, i am sure you know that Many would say its too little time to be of significance

It depends;

As trees has pointed out, overstressing by 10% for a few ms will be of little consequence (provided that the stress is not repeated every other ms!!!)

You need to consider the energy aspect; excess voltage produces some transient internal current in the dielectric; a part of that will go into heating the capacitor. For a rough estimate, consider all the excess voltage and the excess current as dissipation. Can the little fellow survive the stress? You have to take the final decision.

It may not immediately fail, but its life is indeterminate under such conditions and not recommended for reliable operation. AVX capacitor can withstand upto 200% for some micro second duration without dielectric breakdown under life test of capacitor. But it is not for normal reliable operations.

If you're still concerned and if you're using this in a critical application, there should be a TVS (for spike suppression). I hope that TVS diode array (D99 to D103) in your schematic is used for this purpose (but it is not connected in schematics). However, it was clamping voltage of 430V! and this needs to be checked.

But transient spikes will have a lot of energy in a very short time, and spikes that up the voltage far above max are likely to punch through the dielectric.

It's like the difference between gently pushing on a glass door at force above its max load, compared to hitting the door with a wrecking ball at forces above its max load.