Circuit for compensating an offset voltage in an amplifier

Patent metadata

Field	Value
Publication number	US-2016258982-A1
Application number	US-201514802600-A
Country	US
Kind code	A1
Filing date	Jul 17, 2015
Priority date	Mar 4, 2015
Publication date	Sep 8, 2016
Grant date	—

Abstract

A circuit for compensating an offset voltage in an amplifier or a DC component in a signal supplied to the amplifier comprises the amplifier and a first voltage source. The amplifier has at least one measurement signal port and at least two contacts for a supply voltage. Each of two contacts is connected to a different terminal of the first voltage source. The potential at each contact is separated from a ground potential and from an external supply potential.

First claim

1 . A circuit for compensating an offset voltage in an amplifier or a DC component of a signal supplied to the amplifier,
wherein the circuit comprises the amplifier and a first voltage source, wherein the amplifier has at least one measurement signal port and at least two power supply contacts for a supply voltage, wherein each of two contacts is connected to a different terminal of the first voltage source, and wherein each power supply contact of the amplifier is separated from a ground potential.

2 . The circuit according to claim 1 ,
wherein each power supply contact of the amplifier is also separated from every external supply potential.

3 . The circuit according to claim 1 ,
wherein an dynamic voltage range at the output port of the amplifier has a potential which corresponds to the offset voltage or to the DC component of an measurement signal supplied to the measurement signal port plus half of the voltage provided by the first voltage source.

4 . The circuit according to claim 1 ,
wherein the amplified measurement signal is positioned at the mean in the dynamic voltage range at the output port of the amplifier.

5 . The circuit according to claim 1 ,
wherein the potential at each contact is galvanically separated from a ground potential or from an every external supply potential.

6 . The circuit according to claim 1 ,
wherein the contact of the two power supply contacts of the amplifiers having a lower potential is additionally connected to a first terminal of a second voltage source, wherein the second terminal of the second voltage source is connected to the ground potential.

7 . The circuit according to claim 6 ,
wherein the second voltage source provides an voltage substantial equivalent to the offset voltage or the DC component of a measurement signal supplied to the measurement signal port.

8 . The circuit according to claim 1 ,
wherein the contact of the two power supply contacts of the amplifiers having a higher potential is additionally connected to a first terminal of a second voltage source, wherein the second terminal of the second voltage source is connected to the ground potential.

9 . The circuit according to claim 8 ,
wherein the second voltage source provides the sum of the offset voltage or of the DC component in a measurement signal supplied to the measurement port and of the voltage provided by the first voltage source.

10 . Circuit according to claim 1 ,
wherein the first voltage source is a battery.

11 . Circuit according to claim 1 ,
wherein the first voltage source is a voltage provided by AC voltage source via a transformer and a succeeding rectifying circuit.

12 . Oscilloscope having at least one input port, whereby each input port is a measurement signal port in a circuit according to claim 1 .

13 . Probe having a tip, which is connected to a measurement signal port of a circuit according to claim 1 .

Assignees

• Rohde & Schwarz

Inventors

• Siera Thorsten
• Franke Reiner
• Collen Oliver
• Zimmermann Dirk
• Kolbe Andre
• Peschke Martin

Classifications

• H03F1/0211

  with control of the supply voltage or current · CPC title

• H03F2200/261

  Amplifier which being suitable for instrumentation applications · CPC title

• H03F2200/228

  A measuring circuit being coupled to the input of an amplifier · CPC title

• G01R1/06766

  Input circuits therefor · CPC title

• G01R1/30 Primary

  Structural combination of electric measuring instruments with basic electronic circuits, e.g. with amplifier · CPC title