I´m using an INA163 (instrumentation amplifier) with a dual supply, +-5V. But, to get a better performance in my project, I don't want to use a negative source anymore. So, my idea is to connect V- to the ground. But, I tried it and the amplifier responds in a very strange output. I can't figure out why.
When I use the dual supply, my output is something between 3.5 and 4.8 V. Using a single supply, I expect a gap smaller than this. To be exact, the INA163's data-sheet says that there's a lost of 1.8 V in each side of source. So, my gap should be (5 – 1.8) – (0 + 1.8) = 1.4 V. My inputs are very similar, with a small variation of milivolts. The interval measured with dual supply shows me that this small one should be enough. But my output with single supply is always constant (4V) to a very different values of input.
The only change that I did in my circuit is the V- to the ground. I researched in INA163's data sheet looking for something about single supply, but there's anything. Also read a Texas' application report, A Single-Supply Op-Amp Circuit Collection, SLOA058, but I still can't find out what's is happening. Anyone have any idea what's happening?