Hi,
I am using LT1970A for my application. They are supplied by -18V/+18V rail for both input and output stage. Input signal is fed by DAC from -10V to 10V controlled by SW. Op amp is set at -0.5 gain so output is expected -5V to 5V. The circuit is for providing analog voltage to satisfy the DUT.
Sometimes the circuit will stop working during the operation. It will be out of control and end up outputting voltage around -17V. From what I can see is that op-amp is somehow damaged by reading low resistance between pin out and V-. In diode mode of multimeter I can see low voltage drop around 0.5V or even lower between these two pins in both directions. I also compare this to a good circuit I can read much higher resistance and voltage drop only in one direction. So I suspect the chip is bad.
Can I get some knowledge what can cause the IC to be damaged in this way? We test the short circuit capability on the circuit it is working fine and IC can survive. So I think must be some other factors leading to this failure.
Thanks a lot.
