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DC to very slow pulse on the AD8307?

Question asked by groger on Apr 28, 2015
Latest reply on May 2, 2015 by groger

Hi,

 

I'm discovering what a brilliant device the AD8307 (and similar) really is..kudos to the minds at AD that developed this gem.

 

My next project involves detection of very slow moving pulse that will rise from DC - essentially ruling out input coupling caps for HPF. The pulse could go from DC to a peak in 100ms, or it could be 1 second. From the output, it would then go into an ADC.

 

It seems clear an LPF should be used at the input to limit anything above 10Hz.

That works out to f(3db) = 1/(2pi R*C); C = 1/(2piRF) = 1/(6.24 * 10 * 1100) = 15uF

 

From a design perspective, what is the best approach with respect to driving the ADC (should it be buffered)

What are some other considerations I should be thinking about with this type of design?

 

Thanks for your help!

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