Q
How is the bandwidth of current feedback amplifier(for instance AD8174) belimited from top?
A
Three key things to remember about current feedback amplifiers:The inputs are not symmetrical, CFB amps have one high impedance input
(non-inverting terminal) and one low impedance inputs (inverting terminal)
The bandwidth of a CFB amp is independent of the closed loop gain
The bandwidth is set only by the choice of feedback resistor,
For a good background in CFB amps, check our seminar notes "high speed design
techniques"
http://www.analog.com/support/standard_linear/seminar_material/index.html
The datasheet of each CFB amp generally contains theory notes on operation and
often a table of standard external resistor values for different gain
configurations.