A current-feedback amplifier is a well-known component with many uses. Its basic block diagram shows that its input stage is a voltage follower—in practice, a symmetrical emitter follower (Figure 1).

The Sallen-Key lowpass filter is a form of the VCVS (voltage-controlled voltage-source) topology. Unfortunately, the interaction of the op-amp output impedance with the filter input degrades stopband ...

Many improvements to the follower circuit have been proposed over the years. The White cathode follower doubles the output current and makes the transfer function more linear. 1 Adding a common-base ...