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:
Feb. 27, 1990
Filed:
Apr. 21, 1988
Timothy G O'Shaughnessy, Norco, CA (US);
David K Chung, Lake Elsinore, CA (US);
Western Digital Corporation, Irvine, CA (US);
Abstract
A Schmitt trigger having first and second complementary switches is biased to exhibit hysteresis, switching at a high threshold level when the input signal increases, and switching at a low threshold level when the input decreases. The source driver for the Schmitt trigger is coupled to the input of at least one of the complementary switches by transition circuitry, such that the signal level representing one binary value is shifted closer to the level of the power supply voltage corresponding to such binary value without changing the logical value of the signal from the source driver. In one embodiment, the first inverter is a MOS transistor, the threshold level of which is set by a bias voltage applied to the gate of another MOS transistor. The second inverter is a pair of complementary CMOS transistors. In another embodiment, the first inverter also comprises a pair of complementary CMOS transistors. The threshold level is set by selecting the W/L ratio of the CMOS transistors of the first inverter. In another embodiment the first inverter comprises a differential amplifier.