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Old 29th September 2013, 12:21 PM   #11
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I am pretty sure this will end in tears for you.

I would prefer to invest in some de-soldering braid...
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Old 29th September 2013, 04:40 PM   #12
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Those sockets are way too small.
Thanks anyhow.
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Old 29th September 2013, 05:25 PM   #13
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Quote:
Originally Posted by googlyone View Post
I am pretty sure this will end in tears for you.

I would prefer to invest in some de-soldering braid...
I use the socket pins for low current test parameters.
I'm designing some Op Amp test fixture adapters for the LM3886 and LM3875. The first adapter is the LM3875.

Test fixture measurements for LM3875, (Data sheet).

TA = 104 F
Vos = 0.128 mV, (10 mV)
Iibin = +90.9 nA, (1 μA)
Iibni = 85.7 nA, (1 μA)
SR = 20 V/μs, (5 μs)

As you can see, the measurements are much better than the data sheet maximum limits.


Click the image to open in full size.
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Old 30th September 2013, 04:35 AM   #14
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Datasheet maximums are selected to be good enough for the major customers, while being loose enough for most chips to pass and be FAST to test. Measuring nA currents on a production line is fiddly
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Old 1st October 2013, 10:49 AM   #15
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I might have missed the explanation in earlier posts - so apologise if I am asking a repeat question. But...

What is it that compels you to want to measure these parameters? Are you planning to use these devices in some unconventional application?

Remember that these parameters will be quite dependent on temperature and to a lesser extent time etc...
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Old 2nd October 2013, 06:16 PM   #16
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And you will not hear the difference between measured good and measured worse chips.
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Old 3rd October 2013, 06:55 PM   #17
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The amplifier is being used as a bipolar current sink. The amplifiers are selected for several parameters to meet the specifications for the application.
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Old 3rd October 2013, 08:10 PM   #18
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I believe National used a staggered ZIF socket in their proto-typing.
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Old 3rd October 2013, 08:57 PM   #19
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Quote:
Originally Posted by jackinnj View Post
I believe National used a staggered ZIF socket in their proto-typing.
I found a LME49830 demo board parts list, but no socket was listed.
Do you have a link for the socket?

Thanks

Last edited by WSJ; 3rd October 2013 at 09:03 PM.
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Old 4th October 2013, 12:59 PM   #20
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If this is being used as the power stage of a current sink, you would probably be best off going something a tad more complex. I would consider using a low offset drift, low input offset operational amplifier as the sense element, and use the LM3886 as the power stage.

Alternatively, if you are not running this over a large range of currents, you might want to consider the error that the offset / bias of the LM3886 introduces, and size the current sense element appropriately.

But this is just me.
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