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MCP3421 absolute maximum ratings
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mc172:
I'm looking at this datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/22003b.pdf
Two things are a bit confusing to me. On the second page are the absolute maximum ratings for the device.
The datasheet says that the current on the input pins must not exceed 2 mA, but the input impedance is 2.25 M \$\Omega\$ so how could it ever get anywhere close? VDD max is 7 V...
The only thing I can think it could be is when the inputs exceed VDD + 0.3 V and the ESD diodes start conducting, but 2 mA seems pretty low for that.
The datasheet also says "output short circuit current.... continuous" and then 2 lines later says "output current..... 10 mA". Which is it?
wraper:
It means that ESD diodes are quite weak and are rated only for 2 mA.
wraper:
Max output current is not related to ESD diodes.
magic:
I would read it: don't allow output over/undervoltage or shorting to VCC while the chip drives low, if any of that causes the output current to exceed 10mA.
Not sure whether shorting to VCC while the chip drives low causes that limit to be exceeded or not. Perhaps that's what they meant? Either way, it's a pathological situation which doesn't happen in normal operation.
mc172:
Thank you chaps.
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