3. Current-controlled buck converter in sliding mode

Figure 5 shows the principle of voltage regulation using a linear regulator. The small-signal transfer function linking the variation of the output voltage to the variation of the reference voltage (useful for analyzing the frequency behavior of the closed-loop converter), is second-order in continuous conduction. The development of this transfer function is beyond the scope of this introductory article. Following a sudden change in load, e.g. if the load loses half its resistive value, the output voltage suddenly drops, as the current to be supplied to the load increases, and the output capacitor, of reasonable...