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I don't find it confusing, though I usually use the term 'fully differential amplifier' for the amplifier that has differential input and output (even though usually those are high speed).
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An example for a low speed, high voltage, cheap-ish (and precision to boot!) fully differential amplifier is TI's
THP210(...)
but ultimately, it's the best to use very much matched resistors.
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To automate such selection tasks in general, I've made up a python script.For an arbitrary example of "tightest 8 values from the list of measured examples", it looks like this:
grouping_optimizer.py 8 6.932 6.939 6.9155 6.8915 6.905 6.909 6.936 6.943 6.9355 6.9355 6.933 6.943
Average value 6.93712
Error sum 3928.14
Average error 491.02 ppm
With these elements and corresponding errors:
(6.932, 6.939, 6.936, 6.943, 6.9355, 6.9355, 6.933, 6.943)
['-738.78', '270.28', '-162.17', '846.89', '-234.25', '-234.25', '-594.63', '846.89']
It can also be asked for a specific target value as well:
grouping_optimizer.py 8 6.932 6.939 6.9155 6.8915 6.905 6.909 6.936 6.943 6.9355 6.9355 6.933 6.943 --target 6.918
Average value 6.92519
Error sum 15394.62
Average error 1924.33 ppm
With these elements and corresponding errors:
(6.932, 6.9155, 6.905, 6.909, 6.936, 6.9355, 6.9355, 6.933)
['2023.71', '-361.38', '-1879.16', '-1300.95', '2601.91', '2529.63', '2529.63', '2168.26']
It works happily with multiple elements of the same value, can also show the iterations and handle priority elements much like the
resistor divider ratio optimizer.
With this and an grid of measured examples on a piece of paper, quite a tight match is easily achived, for small batches. The "divider optimizer" can be used in the same vain to automatically get multiple "equal ratio dividers" from "excessive examples of random measured resistors". If they are measured at the same time with a warmed up instrument under stable conditions, the absoulte errors (like calibration) cancel out. As a bonus the "arbitrary ratio" of the divider comes free, within the limits of gaussian distribution* of the resistor examples

(*not guaranteed to be gaussian)