Author Topic: ESD protection question from beginner  (Read 1149 times)

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Offline alexg

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ESD protection question from beginner
« on: September 29, 2016, 03:52:48 am »
Hi All, I have a beginner ESD question, I already did some research and know what it is, where it comes from and that it needs to be directed off sensitive parts of the circuit but still somewhat stuck, can you please explain few things or at least provide a push in right direction of research.

1. If you building a handheld device or simply a circuit that lives in an enclosure and powered by AA, AAA or whatever common battery, do you need to consider ESD protection for it.
2. Again, per my understanding, you need to ESD protect (or simply if worded route out high voltage spikes to ground) any data line of the device, does that mean that if you for example have a Microprocessor that has LCD display connected to it and a temperature sensor, and barometer and something else that feeds data into microprocessor, then you need to ESD protect every data line that connecting those peripherals with microprocessor? That would be like 10 lines to protect, let's say it is 4 or 5 data lines to LCD display, then couple data lines for barometer, 1 data line for temperature sensor, etc... All all of those needed to be connected to GND via ESD protection device?
3. If case is made of metal, then no need to ESD protect internals at all?

PS: I apologize for a beginner question but as simple as this sound I can't find answers to those particular questions in all readings that I find on net.

Offline Towz

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Re: ESD protection question from beginner
« Reply #1 on: September 29, 2016, 11:46:27 am »
Most uC and othe cmos devices will have protection diodes included in each pin. However if the application requires an input (like a probe) that could be subject to esd then extra esd protection may be required. Also advisable if it has FET inputs (discrete transistors or FET input opamps). Then...
1. If it has some kind of sensor or probe sticking out then yeah.
2. The uC already has integrated ESD protection. Depending on the location of the barometer it might be wise to add some extra protection (check the datasheet, it might recommend it).
3. Same case a no. 1.

Online wraper

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Re: ESD protection question from beginner
« Reply #2 on: September 29, 2016, 11:59:26 am »
ESD protection is needed on those pins which are exposed to the outside world. If the LCD, sensors, whatever are inside the same enclosure and are permanently connected, there is no need for ESD protection unless for some very specialized reasons which generally do not apply.

Offline alexg

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Re: ESD protection question from beginner
« Reply #3 on: October 01, 2016, 12:07:23 am »
Thanks everyone for replies.

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