Can signal overshoot cause physical damage to component?

Joined: 31 Aug 2026 Posts: 3 Location: China

I found overshoot and undershoot signal in my design, the range is -2.2v~7v, lasting <20nS in every signal duty. The I/O port is 5v tolerance and request the MAX input is -0.5v~6v.
The device also request:
Input clamp current, IIK (VI < 0 or VI > VCC) (see Note 1) ±20 mA
Output clamp current, IOK (VO < 0 or VO > VCC) (see Note 2) ±20 mA

The current of the overshoot or undershoot signal is <6mA.

I don't know whether it will cause damage to the component. For I can't change the circuit now, I have to evaluate the reliability.
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Guest

Is this a one-time build circuit only or is this design going to be built in volume? The reason I ask is because the answer to your question is statistical in nature. Since you are exposing the inputs to voltages larger than the max specified by the manufacturer, marginally weak units operated under aggravating conditions (such as high temp) can be damaged by your overshoots. However, I would venture to say that a large number of devices used in your circuit may be able to withstand your overshoots.

If you want to evaluate this objectively, you should subject a few samples (as large a number as you can spare) to your worst-case overshoot many times (the number will depend on how often this will occur in real life). Check the functionality of the units after every stress. If all samples survive even with exposure to hundreds of hits, then you have a good idea that your overshoots are unlikely to kill the unit.

Bro

Joined: 31 Aug 2026 Posts: 3 Location: China

thanks Bro.
I image if it will cause physical damage to component, what is it? Like ESD? Latch-up? or TDDB?
Since the overshoot is far least than ESD voltage and not enough to cause latcu-up, I think whether it will cause TDDB occur. But I don't know the EOT and thickness of the gate oxide. how can I calculate the life-time of the device if we use it under the overshoot.
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Guest

It really depends on the structure of the inputs being subjected to overshoots. For example, if the input is a MOS gate, then the physical damage will most likely be gate oxide breakdown. If the input connects to a capacitor, then a defect in the cap dielectric layer can lead to dielectric punchthrough. TDDB is unlikely because this mechanism is due to cumulative degradation of the dielectric over time, which will not be caused by intermittent spikes. There is no way to predict the outcome by just looking at the circuit and structure. You really need to conduct tests to get confidence in your circuit. Just post your results when you're done with the eval if you want our comments.

Bro

Joined: 31 Aug 2026 Posts: 3 Location: China

The diode of the IO port can protect the device out of ESD damage. The power of the signal overshoot is least than the power of ESD pulse. Why can't it prevent the signal overshoot damage? There are standards of testing the ESD sensitivity and latch-up, Is there standard to analyse the damage of overshoot?
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Posted: Tue Sep 06, 2026 3:08 pm Post subject:

I'm not saying it can't. You asked me the possibilities so I tried to give you scenarios. If you're convinced that your ESD and latch-up tests are enough, then so be it. You are the engineer of the product, so you always have the final say on this. Let's leave it at that.

Bro

Joined: 20 Jun 2026 Posts: 76

Jim Lean,

The protection diode(s) of an input is designed to divert current away from the input to one of the ground or supply nodes (depending on polarity of the esd pulse) at a certain breakdown voltage. It's therefore possible for this diode not to be able to protect your input from mild overshoots that do not reach the breakdown voltage of the diode.

Anyway, I do NOT think your overshoots can cause an instant esd-type damage to your I/O port. However, these MAY have a long-term negative effect on it. If your I/O port has MOS input transistors, then the repeated overshoots can inject 'hot' carriers into the gate oxides of your MOS transistors. This will degrade them over time, e.g., their Vth may shift. That's one possibility I can think of.

FARel Engr