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. 28, 1995
Filed:
Jan. 03, 1994
John E Hanna, Mesa, AZ (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A real-time tracking filter circuit (10) that exhibits accurate zero placement is implemented in a monolithic structure by incorporating a three-input summing circuit (24) and a two-input summing circuit (28). The input signal (12) and a feedback signal (30) are summed and converted to a first current. The first current is integrated for providing a first integrated voltage (18). The first integrated voltage and an amplified input signal (40) and the feedback signal are summed and converted to a second current. The second current is integrated for providing a second integrated voltage as the feedback signal. The second integrated voltage and the amplified input signal are summed for providing the filtered output signal (36). Integration capacitors (20, 32) are grounded to remove parasitic effects that impact the pole-zero frequency response of the tracking filter output.