Hello, I am looking to pass a 1.1MHz 5V square wave through a unity gain buffer. Can anyone recommend an op-amp that I could use that will not distort the square wave. I am hoping to power the op-amp with 5V, does that mean I require a rail-to-rail op-amp? Thank you.

 

I am hoping to power the op-amp with 5V, does that mean I require a rail-to-rail op-amp? Thank you.

I suppose that it would, but why can't you use a logic buffer, such as 74HC125?

 

Why do you need a buffer?
What's the buffer load?

 

Is the exact shape of the waveform important? You will need a very high frequency (100MHz?) opamp to do that.

Bob

 

No mater what You use, its going to have a certain amount of loss, and ringing,
a 5V Supply is not going to get You a 5V Square-Wave, close maybe, but not 5V.
Also, no switch of any kind can create an "instantaneous-response", it's physically impossible.

Now the discussion goes to exactly how much distortion can be tolerated in your Circuit,
and what Voltage-Level is actually required for reliable operation.

Generally speaking,
the "Slew-Rate" when crossing the "Threshold-Voltage" are the only important requirements,
except of course, when there are other specifications that must be met for a particular application.
.
.
.

 

5v , 1.1 MHz, square wave,
sounds like good old fashioned TTL logic,
why you looking at an op amp ?

A logic gate / driver would seem to be a better mach.

 

Even if you had one it wouldn't do you any good. The rise and fall times are the only thing you can play with. They do nothing to reduce the odd harmonics and nothing to reduce the THD.
If you are still undeterred, you can try this one:
OPA847 data sheet, product information and support | TI.com