Differential amplifier design as the preamp of DMM
US9935598B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 2014 |
| Grant date | Apr 3, 2018 |
| Priority date | — |
| Expiry date | Mar 23, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45528
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An amplifying circuit comprises a differential input stage having a first input terminal, a second input terminal, and an intermediate node, wherein the differential input stage is configured to generate a differential current flowing through the intermediate node in response to an input voltage difference between the first and second input terminals. The amplifying circuit further comprises a first current source coupled to the intermediate node, which is configured to provide a first bias current which allows the differential current to vary within a predetermined range. The amplifying circuit further comprises an output terminal coupled to the intermediate node, and a second current source coupled to the intermediate node and configured to provide a second bias current. The second bias current compensates the differential current and the first bias current and produces an output current flowing through the output terminal in a predetermined direction. A measurement device is also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.