Timeline for Absolute Maximum ratings of a device
Current License: CC BY-SA 4.0
11 events
| when toggle format | what | by | license | comment | |
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| Nov 17, 2023 at 6:07 | vote | accept | CommunityBot | ||
| Nov 17, 2023 at 4:08 | comment | added | dandavis | some inputs float when VCC is zero, ex open collector. Most MCU GPIOs are totem poles, and there can be a route back to vcc from an IO. I've see the built-in LED on ESPs glow when powered off but backfed from a GPIO sensor input. It didn't seem to damage it, but you probably don't want to design something where that happens all the time. | |
| Nov 16, 2023 at 21:30 | history | became hot network question | |||
| Nov 16, 2023 at 14:37 | answer | added | Rohat Kılıç | timeline score: 4 | |
| Nov 16, 2023 at 14:08 | answer | added | Turbo J | timeline score: 1 | |
| Nov 16, 2023 at 14:04 | answer | added | CL. | timeline score: 6 | |
| Nov 16, 2023 at 13:33 | comment | added | periblepsis |
And yes, keeping the current minimal helps. Protection diodes can often only handle 1 or 2 mA, at most. Aluminized tracks in the device will have their own limitations, too. (Metal migration, if nothing else.) You probably need to provide specific details about what you are thinking about doing. Not just asking very broad questions like this.
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| Nov 16, 2023 at 13:33 | comment | added | S_G | I don't quite understand your question. What exactly is your rated nominal VCC? If VCC is 5V, your pin can support up to 5.5V if absolute max is VCC+0.5V. Exceeding Absolute maximum ratings usually leads to abnormal behaviour of components in the best, physical destruction in the worst case. | |
| Nov 16, 2023 at 13:31 | comment | added | periblepsis | Provide link to datasheet that illustrates each of the questions you are asking. The maximum voltage to a pin is often less than a diode drop above Vcc or below ground for good reason. But there are usually other specs that relate to this (and protection diodes, lock-up, etc.) Details matter. So links will clarify your question that you may not be able to clarify, yourself. But yes, if Vcc=0 then there will be problems. But it's probably not spec'd well when Vcc=0, either. So who knows? Need datasheet. Even then, there may not be a good answer for Vcc=0. | |
| S Nov 16, 2023 at 13:27 | review | First questions | |||
| Nov 16, 2023 at 14:16 | |||||
| S Nov 16, 2023 at 13:27 | history | asked | user355393 | CC BY-SA 4.0 |