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Old 1st October 2012, 01:29 AM   #11
WSJ is offline WSJ  United States
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Originally Posted by john curl View Post
WSJ, did you ever know about or use the Fairchild IC tester? I supervised the building of one at Friden in 1966, following Fairchild's instructions. Used it to characterize uA709's.
One was on the bench next to me, I was in the active filter group, but never used the Opamp test fixture.

We used the 709's in our active filters, but at $50 each the production guys said no way when we asked for some. We went undercover with lab coats, during the lunch break we infiltrated the test area and made off with pockets full of 709's. We made active filter test fixtures and tested the 709's, we got enough to ship our orders.
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Old 1st October 2012, 01:37 AM   #12
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Notice I said about half. That certainly would not be one of 'em. Nor the 108 208 308 SuperBeta inputs. The SPA was basically a wammy-bammy curve tracer with 4 VIs, 4standard supplies and several measurement only channels.
Also "most" of the tests could be coorelated to PC data parameters which were only sampled from the lot. I could put a wafer with poor yield on the prober and do the OpAmp tests, the PC Die tests near the poor yield areas or the metal layer test die which brought out actual circuit components individually for measurement.
I worked at a parametric measurement equipment company, we made parametric testers. I have some of the force/measurement boards, +/- 100V and 50 MEG ohm current shunt with a 12 bit A/D to measure low current.

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Old 1st October 2012, 01:50 AM   #13
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Every finished wafer lot had 5 wafers go thru "PC Die" test on our Lomac before probe. If they passed that they went on to an LTX70-77. But this is O.T. and 30 yrs ago as J.C. would say
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Old 1st October 2012, 01:58 AM   #14
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This is a force/measurement board, +/- 100 V, +/- 100 mA and 50 MEG ohm current shunt on the lowest current range with a 12 bit A/D to measure low current. It's used for parametric measurements of the wafer test devices.
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Old 1st October 2012, 02:09 AM   #15
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Eventually, our Test Eng group built what we called the universal OpAmp Test Board and put it and most of the OpAmps on an in house tester. 5lbs of Cotto relays but a very universal set-up. After we got the prober monitor noise away from it.
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Old 1st October 2012, 02:42 AM   #16
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Eventually, our Test Eng group built what we called the universal OpAmp Test Board and put it and most of the OpAmps on an in house tester. 5lbs of Cotto relays but a very universal set-up. After we got the prober monitor noise away from it.
That was a smart move.
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Old 2nd October 2012, 04:56 AM   #17
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Hi WSJ cool stuff
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Old 3rd October 2012, 12:26 AM   #18
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I'm designing some Opamp 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)
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Old 3rd October 2012, 02:00 AM   #19
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Cool
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