Wawa:
Are you sure you can use that diagram?
Most A/Ds must have BOTH inputs voltages within their own VCC-GND.
Or even less than that (common mode range).
I don't see any reference to the A/D's ground (or VCC).
Yes, I am sure. I'm using an ADS1115 which has its upper and lower limits at VCC+0.3V and GND-0.3V. I'll be using the differential measurement to pick up the voltage coming from a hall sensor for current measurement. The hall sensor will output +/- 5V (according to the current flow). I do not expect to see that much (more like +/- 2V) but still I need to protect my inputs (voltage spikes, current).