Multi-stage fully differential amplifier with controlled common mode voltage
US8531238B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 11, 2012 |
| Grant date | Sep 10, 2013 |
| Priority date | — |
| Expiry date | Mar 9, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F3/45183
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Disclosed are systems and methods to achieve a low noise, fully differential amplifier with controlled common mode voltages at each stage output but without the requirement of a common mode feedback loop. Common mode voltages are adjusted by adjusting the currents flowing through the load impedances (bias currents) wherein the currents are derived from one or more voltage-to-current converters based on an impedance that matches to the load impedances of the stages of the amplifier. The amplifier invented is primarily used for amplification of low frequency signals. The amplifier has one or more gain stages applying only one conduction type of transistors of an IC technology that has the lowest transition frequency between 1/f noise and white noise to achieve a low chopping or autozeroing frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.