TLV2462 differential input voltage

Hello Collin,

Its not still clear to me..

Collin Wells said:

"Yes, if you take the negative terminal below -200mV while the positive input is held at GND it may permanently damage the product. "  

 

Actually i asked the scenario like  IN+ at 0V and IN- at +300mV ( not -300mV) say..  ( opamp operating single supply operation of 5V )

Differential input specification i understood like the "The voltage at the non-inverting input with respect to the inverting input." i.e (IN+ )-(IN-) right?

i.e 0V-(+300mV)= -300mV will it damage the opamp to be specific.?

 Also

Collin Wells said:

"This does not mean that a differential voltage, (IN+ - IN-) of -0.3V centered around mid-supply would cause issues (e.g.:  IN+ = 2.65V, IN-=2.35V). "

here also if we consider proper signs IN+-IN- =2.65-2.35=+0.3V right? not -0.3V and obviously its <VDD+0.2 spec and  it will be in limits

So inorder to  simplify my question I would like to ask

" if my inverting terminal goes more than non inverting terminal by say 250mV will it damage the opamp? "

As long as the voltages applied the two input terminals are both within -0.2V to +5.2V there will not be any issues. 

Out of curiosity, are you pulling the two inputs of the op amp apart on purpose or does it happen due to a fast transient on the input/output?  Negative feedback will force the two inputs together unless you're operating the op amp in an open-loop configuration for a comparator function.  If you're using the op amp as a comparator you may find better performance if you use a dedicated comparator.

If what you are stating is correct then I suppose this specification is common mode input voltage range and not differential mode input voltage specification..
And datasheet stating like this is misleading/ or an error.

Hi Stephen,

Just to be sure we provide you with the most accurate information we pulled out the original design schematics for this product and have confirmed that the specification is definitely an absolute limit for each input and not a differential limit as stated. There are not any clamp diodes or other circuitry between the inputs that would create a differential voltage limit within the supply rails of the product.

We're in the process of updating many of our datasheets and will make these revisions during the update.

Hi Collin,

Thank you very much for the confirmation. We are operating this in closed loop only, but some transient conditions could give rise to discussed scenario..just wanted to make sure that it wont damage the part.

Thanks for the support.

Regards,

Stephen Thomas

Hi Collin ,

I would like to confirm one more thing, as you have said the device doesn't have any clamp diodes/other circuitry in between the inputs to generate a differential input voltage specification, then actually what will be the safe limit of differential voltage this opamp can safely handle.?

is it like -0.2 to VDD+0.2 on one input while the other input is GND ed is safe for operation.?

I know it seems weird pulling apart the opamp inputs in closed loop operation, but I'm asking this to understand a specific scenario being faced in our circuit .

So can you please check with your original IC design schematics a let me know the exact differential voltage value it can handle ?

Thanks for the support,

Awaiting your reply

Thanks & Regards
Stephen

Stephen,

A short answer to your question is YES; in single supply application, you may have one input grounded (0V) while the other input is anywhere between -0.2V and Vdd+0.2V; actually in a worst case, one input may be 0.2V below negative rail while the other input is 0.2V above positive rail.

Hi Mark,

Thank you very much for the reply & clarification.

Regards,
Stephen