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Message ID: 4774     Entry time: Tue May 31 16:07:57 2011
Author: Larisa Thorne 
Type: Configuration 
Category: Electronics 
Subject: Seismometer Box Update 

 (Continuation of this)

 

I plugged the circuit into the LISO program to generate the graphs below....the first graph is a plot of frequency (f, in Hz) versus gain (in dB), and frequency (f, Hz) versus phase (in degrees). Also included is the second graph, which is a noise plot of all circuit parts which contribute to the total noise of the circuit.

 

The only issue I had was that two of the op amps I'd picked (see third attachment for the original circuit diagram) for the circuit were not in LISO's op amp library. So I replaced THS4131 (from the voltage buffer part) and AD826 (from the ADC driver part) with AD797 and LT1037, respectively in order to generate the plots below....   

 

There are notes calling the AD797 "ultra low noise, low distortion", whose data sheet can be found here: AD797 

Notes also call LT1037 "low noise, high speed precision op amp", whose data sheet can be found here: LT1037

 

I've put these in temporarily only, as I don't know if they are appropriate choices for the job or even if we have them. Suggestions?

Attachment 1: SeisBoxLISOplot1.pdf  26 kB  | Show | Hide all | Show all
Attachment 2: SeisBoxLISOplot2.pdf  41 kB  | Hide | Hide all | Show all
SeisBoxLISOplot2.pdf
Attachment 3: STS2diagram_original.pdf  43 kB  | Hide | Hide all | Show all
STS2diagram_original.pdf
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