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dudi_g
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Maximum input voltage in Analog Input

Hi,
We thought about using piezoelectric device as an analog input to our DA145580.
The problem is that the piezo sourcing high voltage and negative voltage, which measured sometimes as +10V and -10V.
I'm afraid that those high voltages are bad for the MCU- but I'm not sure since i couldn't find any information about the maximum input voltage allowed or about the protection diode you probably have on the GPIOs. Beside that,
Please give me the information and tell me where its written down.
If its a problem- please advice what should I conncect to the piezo input to limit the voltage.
Beside that- I couldn't find information about the maximum current each GPIO can supply. I heard that its about 5mA from your support, but don't you write it down anywhere?

Thanks,
Dudi

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summer20100514
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Joined: 2014-12-30 05:01
Maybe you should design one

Maybe you should design one circuit which use one amplifier to limit the output voltage.

MT_dialog
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Joined: 2015-06-08 11:34
Hi dudi_g

Hi dudi_g

The information about the maximum input voltage allowed are located in the datasheet Table 281 : Recomended operating conditions. VPIN(default). About the maximum current GPIO's can supply you can find it in table 290 Digital Input/Output: DC Characteristics (VOH(VBAT3V)) and (VOL(VBAT3V)) also in the datasheet. We cant recommend a suitable circuit to limit the voltage, you should find a suitable way to do that and test it.

Thanks MT_dialog

 

dudi_g
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I can see it in V3.1

I can see it in V3.1 datasheet. Thanks.
summer20100514, Now that I know my limits i'll think of a way to do it with an amplifiers/diodes.

Thanks,
Dudi

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