High frequency self-compensation of current-feedback devices

The authors examine the performance of a current-feedback operational amplifier configured as a closed-loop voltage amplifier in two extremes of operation, unity gain and high gain, and suggest methods to extend the frequency response of each by self-compensating these circuits. Mechanisms for high-frequency self-compensation are evident within the transfer function of the device. The authors exploit this feature to achieve high-gain and high-bandwidth structures. The compensation at high gains is achieved by reducing the input impedance of the op-amp, thus reducing high-gain bandwidth roll-off. The frequency performance of an op-amp configured as a unity gain buffer is significantly improved by taking the output from the input side of the device