Topic summary
Current buffer
Extracted from the Wikipedia article Buffer amplifier.
Current buffer
Typically a current buffer amplifier is used to transform a current signal with a low output impedance from a first circuit into an identical current with high impedance for a second circuit. The interposed buffer amplifier prevents the second circuit from loading the first circuit's current unacceptably and interfering with its desired operation. In the ideal current buffer (Figure 1 bottom), the output impedance is infinite (an ideal current source) and the input impedance is zero (a short circuit). Again, other properties of the ideal buffer are: perfect linearity, regardless of signal amplitudes; and instant output response, regardless of the speed of the input signal.