A PLL-based high-stability single-inductor 6-channel output DC-DC buck converter

Cost and size are very important issues for power-management ICs (PMICs), in particular for portable systems where typically multiple voltage levels are required to achieve multi functionality. To meet these requirements, a single-inductor multiple-output (SIMO) switching converter is a very strong candidate. SIMO converters have been the subject of many recent studies and reports [1–3]. The presented converters uses the current-mode controller and PWM with a constant switching frequency. However, designing the feedback control loop of the PWM converters is not an easy task since their stability inherently depends on the load conditions.