What\s the difference between a voltage feedback amplifier and a current feedback amplifier?
The internal circuitry of the two types of op-amps are different, and these two types of op-amps are not necessarily interchangeable in a given configuration. Voltage feedback op-amps are constrained by their internal design to have very low input bias currents, but the differential input voltage is unconstrained internally and is only constrained when external feedback applied around it. Conversely, for current feedback op-amps, the differential input voltage is constrained internally, but the input bias current is unconstrained by the internal design to be low, and is only constrained when external feedback applied around it. Although most colleges do not yet teach the basics in current feedback amplifiers, there are many advantages to using them, especially in high speed applications. See the following Application Notes: OA-30, Current vs. Voltage Feedback Amplifiers OA-07, Current Feedback Op Amp Applications Circuit Guide OA-13, Current Feedback Loop Gain Analysis and Performance
