What does unity gain buffer mean?

[pnak]

I was looking at a layout for the mosfet boost and it said that this was an enhanced layout / when in bypass the circuit acts as a unity gain buffer not true bypass. What does that mean?

[Mark Hammer]

That means that it:

a) Provides no gain (i.e., signal level out = signal level in), hence "unity gain" (gain = 1)

b) Provides a lower impedance for the next device to "see" than if the next device was "looking at" the signal source instead (hence "buffer).

[pnak]

Thanks Mark

I this an advantage over true by pass.