16 Aug
2015
16 Aug
'15
2:41 a.m.
On 08/15/2015 11:18 AM, Douglas Taylor wrote:
I have a number of laboratory instruments that are
from the 1990 time
frame. They produce digital data that is the digitized signal from a
detector, the data can be from 512 to 65K samples long. The ADC used
in these instruments is a 16bit 100ksample/sec design. The ADC is in
a 3 by 4 inch metal box with a row of pins on each long edge.
I think some of them are failing because I get the full 16 bit
resolution from one machine, but not the others. This was determined
by taking the digital samples and sorting the values and computing the
increments between the adjacent values. In some cases the output
looked like 14 bit resolution and in one case 6 bit resolution.
Does anyone have any experience with technology?
Who was the manufacturer? (There is no id on the outside)
What is inside the box? Is it a hybrid circuit?
DDC made a number of hybrid ADCs, but I've never seen one that was 3 x
4"! That's really big. Most likely there is a normal PC board inside,
with a bunch of chips and discrete components on it. Is this box
hermetic, or maybe if you peel back a label, there may be screws that
hold it together.
Jon