Control circuitry for power gating virtual power supply rails at differing voltage potentials

摘要

A single-stage level shifting circuit is used to interface control signals across the boundary between voltage domains with differing positive or ground voltage potentials Asserted states are determined by the difference between the positive voltages potentials and the ground potentials. A lower positive power supply potential is not used to turn OFF PFET coupled to a higher positive power supply potential. Likewise a higher ground power supply potential is not used to turn OF NFETs coupled to a power domain where is significant ground shift. The single stage level shifting circuit has keeper devices that hold asserted states using voltages within the power gated domain.