Hi -
Customer is asking how this part would behave if the signal input went beyond the supply voltage rails? Assuming the design stays within the absolute maximum ratings.
Would the output rail? Or go into a undefined state (cannot predict how would behave)?
Suppose 5V applied across V+ and V-, but signal input is 10V (while keeping current less than 10mA). How would signal output behave?
Tyler
Hi Tyler,
You are correct, the inputs can tolerate higher voltages than the supply, so long as the current is limited to less than 10mA.
I recommend limiting this current to 1mA or less if possible.
Effectively, you will be using the input ESD diodes to forward conduct this current to the VCC rail, clamping the 10V input to something more like 5.7V.
The device gain is 10V/V, so the device will not have any figures for this large of an input signal.
In the case of an input voltage exceeding VCC, the input stage will saturate, and the INA output will go to the rail.
Note, there will be a delay to return back to linear operation after saturating the INA. This value will likely be a bit different than the overload recovery time, as this datasheet spec was characterized with only a saturated output stage.
Please let me know if the customer requires any additional information from us. We are happy to assist with the INA351A design.
Thanks,
Jacob
