Abstract: An output buffer having a first pull-up transistor and a first pull-down transistor connected in series between two nodes of a power supply, their common connection node being connected to the output node. A logic circuit receives an input signal at a logic level and controls the voltage at the gates of the first pull-up transistor and the first pull-down transistor to provide the logic level at the output node. A second pull-up transistor and a second pull-down transistor are connected in series between the two nodes of the power supply, their common connection node being connected to the output node. A control circuit provides an output indicating when the supply voltage is below a predetermined level.

Abstract: A power efficiency control circuit eliminates short circuit power consumption associated with a CMOS output buffer in a manner that substantially increases the buffer operating efficiency. The technique is implemented to allow for a reduction of power associated with the output buffer pre-driver stage. The methodology employs a power efficiency control circuit that tri-states the output buffer before every transition.