Reliability of a buck power stage may be enhanced by extending the maximum input voltage able to be withstood in the disabled (non-switching) state. During device qualification/testing, a power management unit (PMU) in the disabled state may have its input node subjected to greater than a maximum input voltage permitted for reliability (Vmax). Under such conditions, a force voltage (Vforce) may be selectively applied to the PMU switching node in the disabled state. For a given input voltage (VIN), this reduces voltage across the non-switching transistors of the power stage (and hence the resulting stress) to below Vmax. In certain embodiments, the Vforce applied to the switching node is of a fixed magnitude. In other embodiments, the Vforce applied to the switching node is of a magnitude varying with input voltage. Embodiments may be particularly suited to implement power management for a System-On-Chip (SoC).