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:
May. 09, 2000
Filed:
Jan. 26, 1998
James P Berthold, North Attleboro, MA (US);
Keith W Kawate, Attleboro Falls, MA (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A capacitive transducer (10) which provides an output voltage in response to the application of a mechanical stimulus such as pressure or acceleration includes a signal conditioning integrated circuit (12) to which are connected a variable capacitor (C.sub.VAR), a reference capacitor (C.sub.REF), a linear correction capacitor (C.sub.LIN) as well as an integrating capacitor (C.sub.INT) and associated filtering components. The linear correction capacitor (C.sub.LIN) is used to offset a fixed parasitic charge associated with the variable capacitor. Any net error charge appearing on a detect, common node (pin 4) between the variable capacitor and the reference capacitor is cancelled out by means of an analog feedback network (22). In a modified embodiment a thermal compensation network (40) allows for correction for thermal error at a second temperature without having any affect at a first temperature.