(As a follow-up to an earlier question answered by the community - thanks!) So I've got the test circuit setup using the HCPL 7520 (datasheet) now and planning to use an Arduino Uno to measure the voltage at the VOUT.
I've done some tests now though and the VOUT seems to be too off. Below, I've got vRef voltage-divided to 4.41V and the VIN+ to 154mV. The rough VOUT I was expecting was VIN * GAIN = .154 * (4.41/.512) = 1.32V. But I read 3.05V at VOUT and, once adjusted (by -vRef/2 by looking at Fig.5 in the datasheet), I get 0.845 which is completely off.
(Pls ignore pin numbers in the diagram)
Another attempt was VIN+ = 104mV, expected = 0.89V. But I read 2.73V at VOUT, which adjusted becomes 0.525V. Again, not right.
I'm clearly doing something wrong - could anyone correct me or point me to the right direction?