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I've seen on designs where there is a TVS transient suppression diode on the voltage supply. For example, when the voltage supply is say a wall plug.

However, are such diodes really necessary in a battery powered system? I can't think of any way where the battery supply could "overshoot" the rated voltage.

cksa361
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    When a battery is disconnected, a regulator may go through a period when its output is at higher potential than its input. Many of them require external protection (reverse bypass fast diode) for these events, but not a TVS. – tyblu Jan 14 '11 at 13:40
  • You probably need ESD protection. Shocks from human beings can be thousands of volts. I'm not sure of the difference between TVS diodes and ESD protection diodes. – endolith Jan 20 '11 at 22:38

2 Answers2

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It could still happen. Static discharge is one method, inductive switching is another, or perhaps some odd grounding issues bumping up voltages. I would still use TVS diodes on sensitive components.

AngryEE
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If you have ESD-sensitive device inside, it may die when user replaces the battery and touches contacts. Other than that, I can't think of anything.

BarsMonster
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