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:
Sep. 03, 2002
Filed:
Jan. 27, 2000
Yamaha Corporation, Hamamatsu, JP;
Abstract
An A/D conversion apparatus is provided, which is capable of securing a wide dynamic range of A/D conversion with a simple construction through suitably switching the input gain of the input analog signal between predetermined levels. An input gain control device controls gain of an input signal based on a control signal. A &Dgr;&Sgr; modulator carries out oversampling of the input signal having the gain thereof controlled by the input gain control device to convert the input signal to data of one bit. A detecting device detects a peak value of the input signal based on the data of one bit. A gain control device generates the control signal based on the peak value detected by the detecting device in a manner such that the input signal having the gain thereof controlled falls within a predetermined range. To effectively reduce noise of the output digital signal while securing a wide dynamic range of A/D conversion, the &Dgr;&Sgr; modulator may also control the gain of the input signal based on the control signal to a predetermined value (1/A) smaller than 1, and the decimation circuit may have a gain of a second predetermined value (A) for compensating for the gain of the input signal controlled to the predetermined value (1/A).