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LM2901 with one input outside the input common mode range

JSimo.19
Associate II

In the data sheet for TSX339 it says in chapter 6.1:

 "The output state is guaranteed as long as one input remains within the common mode

input voltage range (defined in the operating conditions table), and the other input remains

between -0.3 V and 16 V (meaning that one input can be driven above VCC+)."

Is the same true for LM2901, i.e. one input within the common mode input voltage range and the other input between -0.3 V and 36 V?

6 REPLIES 6
MikeDB
Lead

I believe so yes.

JSimo.19
Associate II

Thanks for answering but I would not select this circuit though until someone from ST says that this is really the case.

MikeDB
Lead

Select which - the TSX339 or the LM2901 ? The LM2901 is a generic part from numerous manufacturers and it was this part your question seemed to be addressing.

JSimo.19
Associate II

The circuit I would like to use is the LM2901 from ST if I can trust it only needs one of the input pins to be inside the specified common mode range and still have the right "result" on the output pin

MikeDB
Lead

Well as it's a generic part I doubt ST even designed it - they probably just copied the original and that was forty years ago so no-one will give any guarantees. Why not play safe and use resistive dividers on both pins to bring the voltages well within the rail voltages ?

JSimo.19
Associate II

I see I had missed that this is already guaranteed in note 4 below table 3.