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:
Jun. 21, 2005
Filed:
May. 17, 2002
Tom Youssef, Dallas, TX (US);
Tom Youssef, Dallas, TX (US);
STMicroelectronics, Inc., Carrollton, TX (US);
Abstract
A circuit and method are disclosed for detecting activation of a switch, such as a mechanical switch, having a first terminal coupled to two or more voltage sources, with each voltage source providing a distinct voltage level representing a logic high level. The circuit includes first circuitry, having an output coupled to the switch for initially placing a first voltage across the switch representative of a logic low level. The circuit further includes second circuitry having an input coupled to the switch for sensing a voltage differential appearing across the switch and an output for indicating whether the voltage appearing across the switch is at any voltage representative of the logic high level, the second circuitry being controlled to selectively eliminate static current drawn by the circuit based upon the value of the output of the second circuitry.