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Sample and hold and A/D

M

Mark

Jan 1, 1970
0
Do I need to use a sample-and-hold? I'm using a 12 bit
successive-approximation A/D converter to read 0 - 10 volts from a
pressure transducer. No large or "fast" changes are expected from the
transduced output. I'm plan to sample the transduced output voltage at
5 HZ.

Thanks,

Mark
 
M

Mark

Jan 1, 1970
0
I'm using an AD574A. I need to use this "Old technology" beacuse it is
for a HI REL application. I need a QPL part and no CMOS because of
radiation concerns. The 574 is an "old workhorse" available as a QPL
part and is all bipolar. The conversion time is 35us. I plan to have a
differential buffer amp ahead of the converter. This amp will have a
simple RC low pass filter set at about 100Hz. This should slow things
down alot. Unfortunally, I can't find an all bipolar (except for the
hold cap) QPL A/D with the S&H built in. Also, fortunately, the
application does not require high accuracy. The strain gage pressure
transduced data sheet I'm looking at showns a 5.000 +/- 0.050 volts for
a full scale output. That seem like a lot of "slop" to me. The system
will be calibrated end-to-end using accurate pressure inputs and errors
will be corrected in the software.

Mark
 
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