Post subject: Setup question for signal source and
buffer Posted: Fri Oct 27, 2006 11:10 am
Joined: Fri Apr 07, 2006 6:10 pm
I need your
practical opinion from experience, if any. I have a signal source.
Part of this signal needs to be sampled. One sampling process involves
detecting whether the signal is there or not. Another sampling process
will try to detect whether the signal amplitude has surpassed a
Just assume that the signal is a low frequency
signal at 38 kHz.
Would it be optimal to do the following
- use a quad opamp package and configure three of
the opamps as voltage buffers / follower.
- tie the input of
the three opamps to the same node
- connect the signal source
to this common node
The first opamp would just replicate
the signal source and send it unprocessed. The 2nd and 3rd opamp
would do the sampling processing schemes.
Does this sound
Or would it be ok to skip the buffer setup and directly
interface the signal source to a common bus that branches off directly
to the sampling sections? This is assuming that the two sampling
schemes utilize op amp inputs to do the signal detection and peak
Posted: Fri Oct 27, 2006 11:22 am
Fri Feb 17, 2006 12:07 pm
Location: London UK
At such a low frequency, I would have the first OA as a voltage
The output would go to the second stage as a
full-wave detector with a time constant well in excess of the carrier
cycle time (ie LPF).
The output would split two ways.
way to a Schnitt Trigger to act as the "Signal/NOT signal" output,
with the trigger level set just above noise (assuming this level
The second way would be to another Schmitt Trigger
with an adjustable trigger threshold set to whatever level you are
If only we had a simple Drawing Tool.