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What factor decides how much of current would be drawn out from GPIO pins of CY8C5868AXI-LP035?
I having my microcontroller being run on 3.3 V. So output from GPIO pins would be on 3.3 V logic. Now some of these GPIO pins go as inputs to data acquisition system for which I am using AD7606 (Analog Devices part). So do I connect GPIO pins directly to AD7606 or should I have resistance in between?
NOTE: AD7606 logic input can sink/source 2 uA.
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PSoC 5LP
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Since your device only sinks 2µA there will be no problem when the VDD voltage levels of your PSoC and the AD7603 are the same.
Bob
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There are AC considerations, eg. trace L causing under/overshoot. This
can in some circumstances require series R on the order of tens of ohms
to clean up transients due to fast edges. You can also overcome this by
setting pins to slow slew rate. But that only fixes PSOC outputs, not inputs
driven by fast logic from A/D interface.
Layout dependancies.
http://www.cypress.com/?rID=43337 AN61290
http://www.cypress.com/?rID=39677 AN57821
Regards, Dana.