Differential amplifier with large input common mode signal range
US7193464B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 2001 |
| Grant date | Mar 20, 2007 |
| Priority date | — |
| Expiry date | Mar 17, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/7203
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A design for a differential amplifier with a large input common mode signal range. The differential amplifier comprises two differential pairs, each having two amplifying MOSFETs. A source follower is connected to the gate terminal of each amplifying MOSFET in one of the differential pairs. A differential signal applied to the differential amplifier comprises two separate signal. Each separate signal is applied to the gate terminals of both the amplifying MOSFET in the differential pair not driven by the source follower and the driven MOSFET of the source follower. The differential amplifier further comprises a pair of switch MOSFETs connected to a current source MOSFET. The switch MOSFETs act to control the distribution of the total current flowing from the current source MOSFET and, consequently, to determine which differential pair works dominantly to amplify the input signals. Each source follower acts to offset the voltage of its input signal to compensate for the range loss due to the bias voltages and the threshold voltages within the differential amplifier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.