I am using an LTC1050 precision opamp. I have applied +-5 V dual rail supply at Vdd and Vss. The output pin 6 is connected to inverted input pin 2. And pin 3 is signal input. So everything is same as an opamp voltage follower should be.
When I power up the circuit , the output voltage swings to +ve rail and in my other samples of LTC1050, it swings to negative rail when no input is connected to pin 3 and it is left floating.
However when I connect actual voltage input to pin 3 then it works fine and precise and follows the voltage properly and neatly.
My concern is why does output swings to either +ve or -ve rail with pin 3 left floating ?
My main issue is to interface the output to an ADC to measure both +ve and -ve voltage output but I cannot stress the input pin of ADC to -0.3 to Vdd+0.3V. I have already damaged one ADC module with this. Please suggest if Opamp is working ok and if I need ADC input protection.