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:
Oct. 14, 1997
Filed:
Jan. 18, 1996
Simon Irving Harrison, Witney, GB;
Paul Anthony Frindle, Witney, GB;
Sony Corporation, Tokyo, JP;
Sony United Kingdom Limited, Weybridge, GB;
Abstract
An amplifier comprises a variable gain analog amplifier for amplifying an input analog signal to generate an intermediate analog signal, the gain of the analog amplifier being switchable between two or more discrete gain values. An analog to digital converter converts the intermediate analog signal into a corresponding intermediate digital signal and a variable gain digital amplifier amplifies the intermediate digital signal. A gain control circuit, responsive to a required gain, selects one of the discrete gain values of the analog amplifier and a gain value of the digital amplifier so that the sum of the selected gain values is substantially equal to the required gain; and whether the required gain is increasing or decreasing is detected. If the required gain is decreasing, a delay circuit delays, by a predetermined period longer than a gain switching period of the analog amplifier, a step change in the gain value of the digital amplifier when the gain control circuit changes the selected discrete gain value for the analog amplifier. This can avoid subjectively disturbing transient boosts in the overall system gain when the analog amplifier's gain is switched.