MOS uni-directional, differential voltage amplifier capable of amplifying signals having input common-mode voltage beneath voltage of lower supply and integrated circuit substrate
US5463347A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 12, 1994 |
| Grant date | Oct 31, 1995 |
| Priority date | — |
| Expiry date | Dec 12, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45394
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An amplifier, preferably an integrated circuit, capable of accepting input common mode voltages below the circuit reference voltage or substrate voltage in the case of an integrated circuit. The amplifier comprises a differential voltage input having higher and lower voltage terminals, a first NMOS transistor coupled between a voltage supply and the higher voltage terminal and a second NMOS transistor coupled between the voltage supply and the lower voltage terminal. A third NMOS transistor is coupled between the voltage supply and the first transistor gate, a fourth NMOS transistor is coupled between the voltage supply and the second transistor gate and a sink resistor is coupled between the gate of the second transistor and the lower voltage terminal. A differential resistor is coupled between the gates of the first and second transistors. The first and second transistors include a source and a backgate coupled to each other and electrically isolated from the substrate with the source of each of the first and second transistors being coupled to a different one of the input terminals. The third and fourth transistors include a source and a backgate coupled to each other and electr…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.