Got My Digikey Flier

May 28, 2014 2 Replies

They are advertising some LT stuff in it. Cool, I guess it's a good thing they support those who gave us that program.



they got a "zero drift" OP AMP on there. Mt associate, being a real engineer and all that, has been making noises about a really low voltage measuring tool. I mean, he kinda likes this old VTVM that has a 0.3 volt scale.



Maybe those OP AMPs would be good to boost it up and just read it on a regular meter.



Just a thought.



One of the things that might be of use would be to be able to measure the poutput of a phono cartridge, and/or use it directly feeding a scope or someting. I dunno, maybe something like that.



Zero drift. I can dig that. Now, how to put it to some good use.


We use a lot of AD8629's, a dual zero-drift opamp, about $2 for the dual. Input offset voltage is 1 uV typ and drift is 2 nV/degC typ.

John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation

The catch with all "zero drift" amplifiers is thermal gradients across the board and the thermocouple voltages in the lead-frame to copper junctions where the amplifier terminals hit the board.

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Copper-kovar is 40uV/C.

Linear Technology's AN-82 has a bit about how it can work in practice.

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See page 8. Taking off a draft-shield produced a 10uV DC shift, and produced a transient 30uV excursion.

Bill Sloman, Sydney

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