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:
Jun. 23, 1992
Filed:
Apr. 05, 1991
Tetsuhiko Kaneaki, Ashiya, JP;
Tsuyoshi Takayama, Osaka, JP;
Abstract
In a digital signal noise shaping requantization circuit formed of a first delta-sigma quantizer (main loop) for executing noise shaping of an input digital signal and a second delta-sigma quantizer (sub-loop) which receives as input signal the quantization error of a local quantizer in the first delta-sigma quantizer, and whose output signal is differentiated and added to the output signal from the first delta-sigma quantizer, the second delta-sigma quantizer includes a feedback circuit for operating on a quantization error of a local quantizer therein, with a predetermined transfer function. The output signal from the feedback circuit, in addition to being fed back to the input of the second delta-sigma quantizer, is also applied to control the operation of the first delta-sigma quantizer such as to modify the value of quantization error of the local quantizer of the first delta-sigma quantizer, for thereby ensuring stable and effective operation of the second delta-sigma quantizer even when the input digital signal attains a high amplitude.