Heyo,
I created a board design for measuring the input offset voltage (Vos) of various DIP op amps.
Github:
https://github.com/pepaslabs/opamp-vosGerbers:
https://github.com/pepaslabs/opamp-vos/raw/master/kicad/releases/v2.1/gerbers.zipSchematic:
https://github.com/pepaslabs/opamp-vos/raw/master/kicad/releases/v2.1/opamp-vos.pdfI'm using the circuit diagram from
http://www.analog.com/media/en/training-seminars/tutorials/MT-037.pdfI'm using the "sijosae" discrete rail splitter, so that you can run it from a single supply (Barrel jack and 0.1" header supply connections are supported).
https://tangentsoft.net/elec/vgrounds.htmlIt supports 4 common footprints: uA741-style single, OP07-style single, dual, and quad.
The Offset voltage is measured by inserting DMM probes into plated through-holes in the board.
For the single op amp footprints, I've included footprints for adding resistors and a trimmer to trim the offset to zero, as well as terminals to measure the resulting resistance values which were required to reach zero offset. Additionally, the trim circuitry can be removed via jumpers.
The board can be populated with different resistance values in order to achieve different gains. I've added some square silkscreen areas for writing on the board with a sharpie to indicate gain or other notes.
This seems to work, but I've noticed two issues so far: 1) the uA741's I've tested seem to be pretty sensitive to EMI (hand waving), which I'm guessing is due to the trim circuitry acting as an antenna, and 2) the plated through hole probe points seem to introduce a bit of a measurement repeatability issue (wiggling your probes to get better contact etc can change the reading a bit).
Board dimensions are 50x100mm, so probably too expensive to order through OSHPark. dirtypcb's might be a better option.
Feedback is welcome, enjoy! I'll also post a few measurements I've taken with it.