Adaptive power multiplexing with a power distribution network

An integrated circuit comprising:

• a first power rail;
• a second power rail;
• a load power rail;
• multiple power-multiplexer tiles coupled in series in a chained arrangement and configured to perform a power-multiplexing operation including switching between coupling the load power rail to the first power rail and coupling the load power rail to the second power rail, the power-multiplexing operation including an overlapping phase in which the first power rail and the second power rail are both coupled to the load power rail;
• and
• means for preventing cross-conduction between the first power rail and the second power rail during the overlapping phase of the power-multiplexing operation by controlling a direction of current flow.

A method for adaptive power multiplexing with a power distribution network, the method comprising:

• providing power to a load power rail from a first power rail via multiple first switching circuits that are distributed along a portion of a circuit load coupled to the load power rail;
• generating a relative voltage signal based on a comparison including a first voltage of the first power rail and a second voltage of a second power rail;
• implementing a power rail transition procedure having multiple phases to transition from the first power rail to the second power rail, including controlling a direction of current flow based on the relative voltage signal during at least one phase of the multiple phases;
• and
• providing power to the load power rail from the second power rail via multiple second switching circuits that are distributed along the portion of the circuit load.

An integrated circuit comprising:

• a first power rail configured to be held at a first voltage;
• a second power rail configured to be held at a second voltage;
• a load power rail;
• a power-multiplexer tile including:
• a first big bi-state switch coupled between the first power rail and the load power rail;
• a first little tri-state switch coupled between the first power rail and the load power rail, the first little tri-state switch capable of being in a one-way state to permit unidirectional current flow from the first power rail to the load power rail and to prevent unidirectional current flow from the load power rail to the first power rail;
• a second big bi-state switch coupled between the second power rail and the load power rail;
• and
• a second little tri-state switch coupled between the second power rail and the load power rail, the second little tri-state switch capable of being in the one-way state to permit unidirectional current flow from the second power rail to the load power rail and to prevent unidirectional current flow from the load power rail to the second power rail;
• and
• power-multiplexer control circuitry configured to place the first little tri-state switch or the second little tri-state switch in the one-way state based on a comparison including the first voltage and the second voltage during a power-multiplexing operation to switch between coupling the load power rail to the first power rail and coupling the load power rail to the second power rail.