[volt-nuts] volt-nuts Digest, Vol 56, Issue 9
jan at 41hz.com
Mon Apr 14 13:46:18 EDT 2014
It was the April 1989 HP journal that made me post the question. The
article makes really good reading about the core of the 3458. It also made
me think about how one could implement the AD with the components available
today and bench instruments. It should not take that many parts to make a
single voltage range, moderate speed, single shot AD using a bench clock /
counter / timer. Just for the learning.
But about the switches there is not much in that article, just the
paragraph quoted by TH, "A custom chip design.." etc.
The article is otherwise seems like a very good starting point for learning
multislope ADs. It seems like it would almost be possible to set up a
spreadsheet with the data given.
I noted that they use a 390pF integration cap which made me wonder what
kind of switches where used, as any FET capacitance / charge would have to
be compensated / cancelled / nulled somehow.
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