Part Number:ISO124
I designed analog circuits using INA128, ISO124, OPA2140.
I set up Amp gain is 1 or 5 by placing a gain resistor (Open or 12.4kΩ) between INA128's pin 1 and pin 8.
INA128 output is ISO124 input.
ISO124's Output is like ISO124's Input when INA128 gain is 1. (Figure TEST 1)
ISO124's Output looks like saturation when INA128 gain is 5. (Figure TEST 2)
INA128's input is 1.4V, so INA128's output is about 7.0V. (Gain 5)
The graph is normal when I measure INA128's output (7.0V).
But ISO124's Output is abnormal. It looks like saturation.
(ISO124's supply power is +13.5V, -13.5V, so 7V INPUT is not saturation range.)
Add
I attached more data graphs about TP3 Measurement.
I don't know why ISO124 Output is different when INA128 Gain is 1 or 5.
Because ISO 124 Input (TP3 Measurement) is normal. (Not saturation range)
ISO 124's abnormal graphs become normal when ISO124's two GND pins is connected. (I don't understand.)
ISO 124 is Isolation Amplifier so I separated GND using NCM6D1215EC (Isolated DC/DC Converter).
