Applying force voltage to switching node of disabled buck converter power stage

摘要

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).

主权项

1. An apparatus comprising:
a buck power stage disposed between a high voltage node and a low voltage node, the buck power stage further comprising a switching node in communication with a load; and a voltage buffer configured to apply a force voltage to the switching node in response to an input signal indicating the buck power stage is in a non-switching state, wherein the force voltage is determined such that, when applied to the switching node, the force voltage is configured to keep voltages applied to the buck power stage within a predefined reliability range.