It has long been known that the simple combination of a depletion-mode MOSFET (and before these were available, a JFET) and a resistor made a simple, serviceable current source such as that seen on ...
Average current-mode control, as shown in Figure 1, is common in continuous-conduction-mode (CCM) power factor correction (PFC). It has two loops: a voltage loop that works as an outer loop and a ...