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:
Jan. 14, 1997
Filed:
Nov. 27, 1995
Reuven Holzer, Herzlia, IL;
National Semiconductor Corporation, , DE (US);
Abstract
An active filter includes a capacitor and a resistor coupled in parallel to an input terminal; a first current conveyor coupled between the capacitor and an output terminal; a second current conveyor coupled between the resistor and the output terminal; and a second capacitor coupled between the output terminal and ground. Proportionality constants between input and output currents of the current conveyors can be adjusted to reduce capacitance in the active filter and reduce the area required to fabricate the active filter in an integrated circuit. The active filter can replace a conventional loop filter in a phase-locked loop of a data separator integrated circuit. In a phase-locked loop, the polarity of a charge pump can be reversed to compensate for current reversal by the current conveyors in the active filter.