Chapter 9. Current Feedback Op Amp Analysis
Current feedback amplifiers (CFA) do not have the traditional differential amplifier input structure, therefore they sacrifice the parameter matching inherent to that structure. The CFA circuit configuration prevents them from obtaining the precision of voltage feedback amplifiers (VFA), but the circuit configuration that sacrifices precision results in increased bandwidth and slew rate. The higher bandwidth is relatively independent of closed loop gain, so the constant gain/bandwidth restriction applied to VFAs is removed for CFAs. The slew rate of CFAs is much improved from their counterpart VFAs, because their structure enables the output stage to supply slewing current ...