The power stage of switching converters can be modeled essentially as a PWM-switch. A switch seems to be far from the kind of circuit element that can be linearized, but it can be. This Part 2 ...

In Seemingly Simple Circuits: Transresistance Amplifier, Part 1– Approximating Op-Amps, the op-amp was approximated from a single-pole, finite gain amplifier to an infinite-gain, single-pole op-amp, ...