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. 28, 1989
Filed:
Jul. 19, 1988
Akira Sogo, Hamamatsu, JP;
Yamaha Corporation, Hamamatsu, JP;
Abstract
A FM demodulation circuit contains an analog-to-digital converter which converts an inputted frequency-modulated (FM) signal into a digital signal of one bit at a timing based on the predetermined clock signal and a differentiation circuit which differentiates the digital signal to thereby output a pulse train whose pulse density is in proportion to a frequency of the inputted FM signal. When the pulse train is supplied to a low-pass filter, the pulse train is converted into an analog signal, which is outputted as a demodulated signal. When the pulse train is supplied to a decimation circuit which includes a weight function generating portion and an accumulator, weighted function values are sequentially accumulated based on the level of the pulse train in the predetermined period so that the demodulated signal can be obtained in the form of a linear pulse code modulated (linear PCM) signal.