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:
Nov. 14, 2000
Filed:
Sep. 23, 1997
Petrus H Seesink, Best, NL;
Endress + Hauser GmbH + Co., Maulburg, DE;
Envec Mess-und Regeltechnik GmbH + Co., Rhein, DE;
Vega Grieshaber KG, Shiltach, DE;
Kavlico Corporation, Moorpark, CA (US);
Abstract
With regard to a significant reduction in the tolerance range or margin to be taken into account in the design of a switched-capacitor circuit which is monolithically integrated by means of enhancement-mode insulated-gate field-effect transistors there is provided at least one opamp. This opamp contains a resistor which determines its quiescent current and is realized as a transistor operated in the permanently current-conducting state. An on-chip clock oscillator generates a clock signal. This oscillator is either an RC clock oscillator, whose frequency is determined by an oscillator resistor, which is realized as a transistor operated in the permanently current-conducting state, and an oscillator capacitor, or a current-controlled clock oscillator, whose frequency is determined by the quiescent current of the opamp. At least one capacitor is charged or discharged during operation by the opam via at least one switch in the form of a transistor clocked by the clock signal.