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:
Jun. 06, 1988
Johnnie F Molina, Tucson, AZ (US);
Robert M Stitt, II, Tucson, AZ (US);
Burr-Brown Corporation, Tucson, AZ (US);
Abstract
A technique for reducing phase shift of a signal passing through a large thin film resistor on an insulating layer includes applying a signal to one terminal of the thin film resistor and also to one end of an underlying doped epitaxial region. The opposite terminal of the thin film resistor is connected to a virtual ground or virtual reference voltage produced by an inverting input of an operational amplifier. The corresponding opposite end of the epitaxial layer is connected to ground or other reference voltage. The voltage gradients produced by currents flowing through both the thin film resistor and the epitaxial layer are equal, so that substantially no incremental charging current flows through capacitance between the thin film resistor and the epitaxial layer. Phase shift of the signal flowing through the thin film resistor is thereby avoided.