Wonder no more....................
Also, "The bandwidth of a current feedback op amp is not greatly affected by the closed loop gain as a voltage feedback amp is", is not true so i have to wonder who made that up. .................
Seriously, that's not what they are saying........................
Seriously though, it sounds like they are stating that there is never a frequency roll off, but it seems they are just relating theoretical aspects of the design of an op amp. Probably their main assumption is that a capacitor can charge with a current source (originating from feedback) in zero time. If what they say is true across the board, then data sheets would not reflect a decrease in cutoff frequency with gain.
You can look on some data sheets for CF op amps to find out the real life truth
"Look at me Ma, i'm using my op amp at 9.7E+15 Hertz!" ha ha.
Please trouble me.Hi again,
Well, AD8001 for example. This was my choice years ago for a digital scope front end, for better or for worse
I'll save you some trouble:
880MHz gain of 1
440MHz gain of 2
I am pretty sure that 880 divided by 2 equals 440 (little joke there)
Hi...Please trouble me.
Where did those response values come from?
I don't see that on the data sheet.
Page 10 (bottom of first column) of the AD8001 data sheet states "Recognizing that G × RIN << R1 for low gains, it can be seen to the first order that bandwidth for this amplifier is independent of gain (G). This simple analysis in conjunction with Figure 5 can, in fact, predict the behavior of the AD8001 over a wide range of conditions."
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by Jake Hertz
by Jake Hertz