Hello, I'm applying a INA199A1 device like adviced in the datasheet. I'm using an RC filter (each diff. input is connected via 22 ohm to the load resistor of 0,033 ohm. Next to this, there is a 100nF cap between the 2 differential inputs). The INA199A1 own supply is 3.3V.
The load resistor is feeding/sensing
a) a +24V supply line in some situations
b) a floating supply line in some other situations (this floating supply line however is connected to ground via a 100K resistor).
I'm experiencing the problem that the 22 ohm resistors become damaged (they open like a fuse) sometimes (especially when the supply line is floating). This would indicate at first sight that the differential input CM voltage is violating the specification of -0.3 to +26V (which I doubt will but will check later). So therefore my question is : is there some kind of clamping diode (to ground) inside of the INA199A1 device ? If not, how can the external 22 ohm feeding resistor ever get damaged while the INA199A1 input resistance is 20kOhm) ?
