I do not know if we have a way to solve this, but my customer is having the following issue with the TLV333:
I designed an amplifier circuit based on the TLV333 and bias the positive input off a bias chain that also biases a gas sensor and a transimpedance amplifier. When the out hits the negative rail the + input sources current and affects the bias chain. I understand this is due to the input protection diodes and EMI parasitic diodes. Is there an alternative low power part with low input offset voltage and current that does not have this issue?
I explained to him that these devices were not designed to go all the way to the rail and he sent the following:
We are able to shut off the TLV333 within a few hundred ms of the output hitting the rail to reduce the problem of disturbing the conditioning of the gas sensor, but we would like to eliminate the problem if possible.
I can send the schematic under a separate email if you want to see it.
Please let me know if you might have a solution that does not involves using a (-) supply voltage. I could not think of another way to do this without introducing a second supply voltage. Is there another way? Is there another chip that might work better?
Thanks for your help with this!
Richard Elmquist
