Patent ID: 7157958

Claim:
An electronic circuit for selecting one of a plurality of input signals for coupling to an output channel of an output buffer, the electronic circuit comprising: a plurality of input terminals; a plurality of pulldown devices configured to provide a separate pathway for each of the plurality of input terminals, each of the pulldown devices being coupled to a common pre-charge node; a select signal terminal coupled to each of the pulldown devices and configured to gate each of the plurality of input terminals; a system power supply having a voltage potential VDD, and a pre-charge supply, with a pre-charge voltage potential VPCHG. the system voltage potential exceeding the pre-charge supply voltage and the precharge voltage potential exceeding the switchpoint voltage during a pre-charge interval, but dropping to and below the switchpoint voltage afterwards; and a pre-charge device to provide the pre-charge voltage potential for the common pre-charge node, the pre-charge device having a first terminal coupled to the pre-charge supply and a second terminal coupled to the pre-charge node to provide the pre-charge voltage potential, the pre-charge voltage potential being both greater than the switchpoint voltage of the output buffer and closer in value to the switchpoint voltage than to the system supply voltage potential, VDD, the output buffer switching logic states when the pre-charge voltage drops below the switchpoint voltage after the pre-charge interval.