Best OpAmp as buffer

[nickagian]

hi!

In an instrument I design, I want to sense the battery voltage using one of the analogue input channels of the internal ADC of my MCU. Due to limited VREF of the ADC, after the battery I have put a simple voltage divider. I am thinking of using an opamp as buffer between the voltage divider and the ADC. How could I choose the best opamp for this job, based on what criteria? Is there any particular characteristic of the opamp that plays important role for a buffer?

For example, I have chosen the LPV511, just because it receives single supply at 3V and its current consumption is very low. Is this opamp ok? Should I look for something different?

Thanks a lot!

 

[MikeMl]

I am working on a similar problem. In my case, the Vref in my MCU is 5V, and I would like to sense battery voltage between 13V and 16.2V. If I used a simple resistive divider, I would not have much resolution with respect to the input range of the AD, so I came up with this:

You could modify it for your voltages. The opamp must be rail to rail out.