AnsweredAssumed Answered

ADA4940 Power down and Supply voltage

Question asked by Andrenaline on Sep 19, 2012
Latest reply on Sep 19, 2012 by Emman.A

Dear engineer zone member,

 

I want to use the ADA4940 in my design, but I have some questions.

The maximum supply voltage is 8V. I would like to use the part on ± 3.3V, so this should

not be a problem am I right? Do the specifications for the disable pin still stay the same?

 

Disabled -Vs +1V    so    ≤ -2.3V

Enabled  ≥ -Vs +1.8V  so    ≥ -1.5V

 

By the way, who has made the choice to disable the device with -Vs!

Al my components in my chain, most of the from analog and also dual supply,

work with positive 0V or 3.3-5V disable pin levels. Only this chip needs -Vs level! :-(

 

So to work around this problem, can I put a pulldown resistor to the negative voltage supply pin (-3.3V),

so that the part is always disabled, and enabled when I put an 0V or 3.3V signal on the disable pin?

 

Or has someone else a better idea? I don't have any place for an level converter.

 

Thanks,

 

Andre

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