Apparatus and circuit for amplifying baseband signal
US8854137B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 14, 2012 |
| Grant date | Oct 7, 2014 |
| Priority date | — |
| Expiry date | Dec 14, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45594
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An operational amplifier circuit is provided. The operational amplifier circuit includes a differential amplifier of a cascade structure and a switched-capacitor type Common-Mode FeedBack (CMFB) circuit. The differential amplifier amplifies a difference between two input signals to output an anode output voltage and a negative output voltage. The switched-capacitor type CMFB circuit averages the anode output voltage and the negative output voltage of the differential amplifier, compares the average voltage with a reference voltage to generate a feedback signal based on a result of the comparison, and provides the feedback signal to the differential amplifier. Therefore, power consumption is reduced and a battery use time of a wireless terminal can be extended. Also, since an operational amplifier gain of each analog filter terminal is not negatively affected, a Direct Current (DC) offset is reduced, thereby improving signal quality.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.