Frederick S Chiu

US Patent:

59660368, Oct 12, 1999

Filed:

Sep 9, 1997

Appl. No.:

8/926174

Inventors:

David L. Hoff - San Jose CA
Frederick S. Chiu - San Francisco CA

Assignee:

S3 Incorporated - Santa Clara CA

International Classification:

H03B 100

US Classification:

327112

Abstract:

A system for buffering input and output signals in a floating substrate technology environment comprises an output pre-driver and an output driver. The output pre-driver includes a pull-up subsystem and a pull-down subsystem, which both receive an output signal and an output enable signal. The pull-up subsystem includes a multistage delay circuit, a current regulation circuit, and a bootstrap circuit, a keeper circuit, an oscillator circuit, and a turn-off circuit, which are coupled together so that a pull-up signal is generated. The pull-down subsystem includes a stagger circuit and a switch circuit that are coupled together to generate a pull-down signal. The output driver includes a pull-up circuit to receive the pull-up signal and a staggered pull-down circuit to receive the pull-down signal. The output driver generates a pad signal used to drive a peripheral device that is coupled to the mixed voltage drive system. A method for a mixed voltage drive system for floating substrate technology is also disclosed.