# What does the condition “f=100Hz” mean for the Gain Bandwidth Product?

In the LT6003 datasheet you can find the following information:

How do I read the Gain Bandwidth Product? I mean there is a typical bandwidth of 2kHz under the condition of f=100Hz and I'm not sure what this condition could mean.

I also did a practical test with the LT6003:

• Simple buffer circuit
• Supply voltage of 10V
• Input signal: sine wave with 5V offset, 2Vpp

Interestingly the signal looks distorted for frequencies above of 150Hz.

At 150Hz, the amplifier gain (and the loop gain in a buffer) is only a factor of 13 or so. That means that any inherent distortion in the amplifier is only divided by a factor of 13 -- and the whole notion of an op-amp is "overcome problems deriving from a crappy amplifier with tons of gain". "Tons of gain" varies by what you're trying to do, but I would say that $$\2^n\$$, where $$\n\$$ is the number of bits of precision you're interested in, is a good first approximation. So, if you're feeding a 16-bit ADC, you'd expect good performance with a loop gain better than 65000.