LMV931-N: Input CM range spec...typo?

Brian Antheunisse

Expert 5195 points

Part Number: LMV931-N

Hi guys,

Could you help me to understand if this is typo in datasheet or this is real issue with this device?

Marked below says typ common mode ip range is from 0.2V to 3V? for a Vcc of 2.7V. I didn’t get this.

Thanks,

Brian

over 5 years ago

0 Bala Ravi over 5 years ago

TI__Expert 6625 points

Hello Brian,
I apologize that the datasheet isn't clear. The datasheet is trying to convey that Vcm range is: (V-) -0.2V to (V+)+0.2V. Notice that this is a rail-rail device. So for a Vs = 2.7V (V- is connected to GND). Vcm range = (0V-0.2V) to (2.7V+0.2V) = -0.2V to 2.9V. This is true at 25C. I hope this helps!

Best Regards,
Bala Ravi

0 Ron Michallick over 5 years ago

TI__Guru*** 139956 points

Brian,

If temperature is less than 85C, then valid input range is -0.2V to 3V which is 200mV below and 300mV above the supply rails.
That is not odd or incorrect. It is common for input range (for a RRI op amp) to exceed supplies be a small amount.
Note at 125C, the valid input range could be 200mV inside (not beyond) the supply rails.

0 Brian Antheunisse over 5 years ago in reply to Ron Michallick

TI__Expert 5195 points

Ron,

Think I get it. The datasheet spec seems to indicate that the MAX at:

25C is V+ plus .2 (2.9V)
85C is V+ (2.7V)
125C is V+ minus .2 (2.5V)

But then the TYP for all three temp ranges says 3V. So we may find that some parts can handle V+ = 3V, but to be safe we should stay under those Max values depending on the temp.

0 Ron Michallick over 5 years ago in reply to Brian Antheunisse

TI__Guru*** 139956 points

Brian,

Yes, you are understanding it correctly.
Typical specs are almost always given for 25C operation. In this case, the word wrap make it look like the typical spec includes other temperatures, however typical applies to 25C.

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LMV931-N: Input CM range spec...typo?