Other Parts Discussed in Thread: INA826
I have made a circuit using the INA317 where I want to measure the open voltage of a load, after it has been charged, but somehow the gain is less than 1. For the Rg, I didn't place any resistor because I wanted a gain of 1. The input+ and input- are disconnected from the circuit and only connected to the load and, when the load is at 1.5V, for example, the output is 0.63V or something like that.
I noticed that with a capacitor placed between input+ and ground, the output gets alot closer. Right now, I have three capacitors, one from Input+ to GND, one from Input- to GND and another from Output to GND and the difference is "just" 100mV.
I need a really high impedance input so as to not disturb the load as I'm measuring the open circuit voltage, that's why I chose this part. The INA317 is being powered by a 3.3V rail.
I have another circuit which I presented here with another issue, where I used the INA826 and that one is working flawlessly but it's being powered by a 10V power rail.
Is there anything I'm missing here? Here's the schematic, I've taken Q1 and Q2 out and am connecting the load directly to their drain.