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:
May. 28, 1991
Filed:
Apr. 26, 1990
Shigenobu Kimura, Hamamatsu, JP;
Yamaha Corporation, Hamamatsu, JP;
Abstract
A digital-to-analog conversion circuit capable of preventing a noise produced in a digital system from mixing in an analog output has an input circuit receiving a pulse-code modulated digital signal, a conversion circuit such as a noise shaping circuit for converting the pulse-code modulated digital signal to a pulse wave signal containing analog amplitude information in a time axis direction, a buffer circuit including an electrically insulated coupling circuit such as an optical coupling circuit for transmitting output of the conversion circuit, and an analog output circuit including an analog low-pass filter for delivering out output of the buffer circuit therethrough. A noise generated in a digital system is intercepted by the buffer circuit and is not transmitted further so that mixing of the noise in the analog output circuit is prevented.