Multiplexer digital input voltage limits

[Jimbo bob]

Hi everyone,

I was going through the data sheet for ADG706_707 multiplexer. I am planning to power it with +2.5V and -2.5V. When I go to the absolute ratings section on page 5 it says:

Digital Inputs . . . . . . . . . . . . . . . . . –0.3 V to VDD + 0.3 V or 30 mA, Whichever Occurs First

and then there is a footnote for it:

Overvoltages at A, EN, S, or D will be clamped by internal diodes. Current should
be limited to the maximum ratings given.

I was planning to feed the digital inputs of the multiplexer (i.e. A0, A1, A2 and A3) with Arduino Mega's digital I/O which I think output 5V as a high voltage. Considering that on page 4, Vinh is 1.7V minimum and Vinl is 0.7 maximum, I am a bit confused whether I can still use Arduino's digital I/O or not with the MUX.

Many thanks in advanced

 

[Harald Kapp]

A simple way to match the arduino's 5V outputs to the ADG706's digital inputs is a 1/2 divider. Use a resistive divider from the arduino's output to GND built from e.g. 2*1kΩ resistors. this will reduce the arduino's output swing from 0V...5V to 0V...2.5V, a perfect match for the multiplexer.

 

[Jimbo bob]

Thank you Harald. It makes sense and it seems that is the best way of going about solving this problem.