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:
Apr. 28, 1998
Filed:
Apr. 30, 1996
Walter S Czarnocki, Hoffman Estates, IL (US);
Thomas J Walczak, Woodstock, IL (US);
Motorola Inc., Schaumburg, IL (US);
Abstract
A ratiometric circuit (40) includes a differential capacitive sensor (42) for sensing a change in capacitance, a differential capacitive detector (46) operatively connected to the differential capacitive sensor for detecting a change in the capacitance of the differential capacitve sensor, an error voltage generator (48) operatively connected to the differential capacitve detector for generating a corrective voltage in response to the detected change in capacitance, and a bias circuit (50) operatively connected to the differential capacitive sensor for generating a bias voltage inversely proportional to and independent of a supply voltage for maintaining the ratiometricity between an output voltage of the differential capacitive sensor and the supply voltage.