Variable gain amplifier and audio device
US8514017B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 8, 2011 |
| Grant date | Aug 20, 2013 |
| Priority date | — |
| Expiry date | Nov 10, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45534
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A variable gain amplifier, to amplify an audio input signal to output an audio output signal at an adjustable gain, includes an operational amplifier having an inverting input terminal, a non-inverting input terminal, and an output terminal to output the audio output signal; an attenuation-rate adjustable feedback circuit to feed back the audio output signal from the output terminal of the operational amplifier to the inverting input terminal of the operational amplifier as a feedback signal, and attenuate the audio output signal and output the feedback signal to the inverting terminal; and an attenuation-rate adjustable attenuator to attenuate the audio input signal for output it as an attenuated signal to the non-inverting input terminal of the operational amplifier. Settings of the attenuation rates of the feedback circuit and the attenuator are combined and a resolution of level of the audio output signal is increased.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.