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US 11,152,901 B2Granted
Amplifier
AssigneeAnalog Devices, Inc.
InventorMichael J. Guidry
Life of this patent
Estimating the term…
Abstract
An instrumentation amplifier including a pair of input amplifiers, each including an input transistor and a feedback current amplifier configured to amplify and feedback an error current from the input transistor. The arrangement can enable a current efficient solution where the amplifier can operate with very low input signals that are close to, or potentially below ground, without requiring a negative power supply voltage.
Claims21
An instrumentation amplifier comprising:
- a first stage configured to generate an amplified differential output based on a differential input, the first stage including:
- a first amplifier including:
- a first transistor, wherein a gate of the first transistor is coupled to a first input of the differential input, and
- a first current amplifier coupling a drain of the first transistor to a first output of the differential output;
- a second amplifier including:
- a second transistor, wherein a gate of the second transistor is coupled to a second input of the differential input, and
- a second current amplifier coupling a drain of the second transistor to a second output of the differential output;
- and
- a resistor network including:
- a first feedback resistor coupling the first output to a source of the first transistor;
- and
- a second feedback resistor coupling the second output to a source of the second transistor,
- wherein the first amplifier further comprises a first cascode device coupled between the drain of the first transistor and an input to the first current amplifier, wherein the second amplifier further comprises a second cascode device coupled between the drain of the second transistor and an input to the second current amplifier, and
- wherein the first cascode device comprises a transistor with a gate coupled to the first input, and wherein the second cascode device comprises a further transistor with a gate coupled to the second input.
11 more elements
An instrumentation amplifier comprising:
- a differential input;
- a differential output;
- a first amplifier comprising:
- a first transistor, wherein a gate terminal of the first transistor is coupled to a first input of the differential input, and
- a first feedback current amplifier coupling a drain terminal of the first transistor to a source terminal of the first transistor and a first output of the differential output;
- and
- a second amplifier comprising:
- a second transistor, wherein a gate terminal of the second transistor is coupled to a second input of the differential input, and
- a second current feedback amplifier coupling a drain terminal of the second transistor to a source terminal of the second transistor and a second output of the differential output,
- wherein the first amplifier further comprises a first cascade device coupled between the drain terminal of the first transistor and an input to the first current amplifier, wherein the second amplifier further comprises a second cascode device coupled between the drain terminal of the second transistor and an input to the second current amplifier, and
- wherein the first cascode device comprises a transistor with a gate terminal coupled to the first input of the differential input, and wherein the second cascode device comprises a further transistor with a gate terminal coupled to the second input of the differential input.
8 more elements
An energy measurement frontend IC comprising:
- an instrumentation amplifier configured to couple to a current sensor and amplify a current sensor signal, the instrumentation amplifier including:
- a first amplifier including:
- a first transistor, wherein a gate of the first transistor is coupled to a first input of the differential input, and
- a first current amplifier coupling a drain of the first transistor to a first output of the differential output;
- a second amplifier including:
- a second transistor, wherein a gate of the second transistor is coupled to a second input of the differential input, and
- a second current amplifier coupling a drain of the second transistor to a second output of the differential output;
- and
- a resistor network including:
- a first feedback resistor coupling the first output to a source of the first transistor;
- a second feedback resistor coupling the second output to a source of the second transistor;
- and
- a connecting resistor coupling the source of the first transistor to the source of the second transistor,
- wherein the first amplifier further comprises a first cascode device coupled between the drain of the first transistor and an input to the first current amplifier, wherein the second amplifier further comprises a second cascode device coupled between the drain of the second transistor and an input to the second current amplifier, and
- wherein the first cascode device comprises a transistor with a gate coupled to the first input, and wherein the second cascode device comprises a further transistor with a gate coupled to the second input.
12 more elements
An instrumentation amplifier comprising:
- a differential input;
- a differential output;
- a first amplifier comprising:
- a first transistor, wherein a gate terminal of the first transistor is coupled to a first input of the differential input, and
- a first feedback current amplifier coupling a drain terminal of the first transistor to a source terminal of the first transistor and a first output of the differential output;
- and
- a second amplifier comprising:
- a second transistor, wherein a gate terminal of the second transistor is coupled to a second input of the differential input, and
- a second current feedback amplifier coupling a drain terminal of the second transistor to a source terminal of the second transistor and a second output of the differential output,
- wherein:
- the first amplifier further comprises a first cascode device coupled between the drain terminal of the first transistor and an input to the first current amplifier, and wherein
- the second amplifier further comprises a second cascode device coupled between the drain terminal of the second transistor and an input to the second current amplifier, and
- wherein:
- the first amplifier further comprises a first voltage shift device configured to raise a body, voltage of the first transistor to above a source voltage of the first transistor;
- and
- the second amplifier further comprises a second voltage shift device configured to raise a body voltage of the second transistor above a source voltage of the second transistor.
13 more elements
An instrumentation amplifier comprising:
- a first stage configured to generate an amplified differential output based on a differential input, the first stage including:
- a first amplifier including:
- a first transistor, wherein a gate of the first transistor is coupled to a first input of the differential input, and
- a first current amplifier coupling a drain of the first transistor to a first output of the differential output;
- a second amplifier including:
- a second transistor, wherein a gate of the second transistor is coupled to a second input of the differential input, and
- a second current amplifier coupling a drain of the second transistor to a second output of the differential output;
- and
- a resistor network including:
- a first feedback resistor coupling the first output to a source of the first transistor;
- and
- a second feedback resistor coupling the second output to a source of the second transistor,
- wherein the first amplifier further comprises a first voltage shift device configured to raise a body voltage of the first transistor to above a source voltage of the first transistor, and
- wherein the second amplifier further comprises a second voltage shift device configured to raise a body voltage of the second transistor above a source voltage of the second transistor.
11 more elements
Dependencies are inferred from the claim text.