The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 06, 1999
Filed:
Jun. 25, 1997
Thomas R Schneider, Anaheim, CA (US);
Adaptec, Inc., Milpitas, CA (US);
Abstract
An integrated circuit provides for an output driver having a quick turn-on characteristic as well as a maximum V.sub.OH level limited to the maximum SCSI specification limit. The output driver's V.sub.OH is controlled by a resistor divider network, connected between a pull-up signal source and a pull-up output device, and which functions to reduce the gate voltage on the output device such that its maximum V.sub.OH level is limited to the SCSI specification. The quick turn-on characteristic is implemented by coupling a transfer gate in parallel with the series resistor of the resistor divider network, and bypassing the series resistor during a first portion of the pull-up turn-on time of the output driver. A feedback circuit is connected between the output driver output and the transfer gate bypass circuit, in order to turn the transfer gate off when the output voltage reaches a particular trigger value, thus removing the bypass from the series resistor and allowing the resistor divider network to function normally and limit the output driver's pull-up to the maximum SCSI V.sub.OH limit. The transfer gate is further configured to allow an SCSI device incorporating the circuit to be hot-switched onto and off of an active SCSI bus.