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:
Dec. 05, 2000
Filed:
Apr. 26, 1999
Yoshihisa Minami, Otsu, JP;
Masaru Yasuda, Nara, JP;
Abstract
An active filter circuit (a band stop filter type or a band pass filter type) having high Q value and high efficiency and which is suitable for integration has an input signal vi inputted from the input terminal supplied to the non-inverting input terminal of the first differential amplifier. The output terminal of the first differential amplifier is connected to the non-inverting input terminal of the second differential amplifier, and the first capacitor 3 is connected between this connection line and the alternate current ground. An output of the second differential amplifier is connected to the non-inverting input terminal of the first differential amplifier via the second capacitor, the inverting input terminal of the first differential amplifier, the inverting input terminal of the second differential amplifier 4, the non-inverting input terminal of the third differential amplifier, the output terminal of the third differential amplifier and the output terminal of the active filter circuit. An inverting input terminal of the third differential amplifier is connected to alternate current ground. The output of the second differential amplifier becomes the output signal vo of the active filter circuit.