Invention Grant
- Patent Title: Differential amplifier design as the preamp of DMM
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Application No.: US14539599Application Date: 2014-11-12
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Publication No.: US09935598B2Publication Date: 2018-04-03
- Inventor: Hong Yao , Yong Yang , Hua Qui
- Applicant: Fluke Precision Measurement Ltd.
- Applicant Address: GB Norwich
- Assignee: Fluke Precision Measurement Ltd.
- Current Assignee: Fluke Precision Measurement Ltd.
- Current Assignee Address: GB Norwich
- Agency: Seed IP Law Group LLP
- Priority: CN201310572915 20131113
- Main IPC: H03F3/45
- IPC: H03F3/45 ; G01R19/00 ; G01R15/12

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.
Public/Granted literature
- US20150130483A1 DIFFERENTIAL AMPLIFIER DESIGN AS THE PREAMP OF DMM Public/Granted day:2015-05-14
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