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US 11,095,260 B2Granted
Amplifier with low drift biasing
AssigneeTexas Instruments Incorporated
InventorRavpreet Singh
Life of this patent
Estimating the term…
Abstract
An amplifier includes an input transistor, an input terminal, a first current source, a cascode transistor, and a second current source. The input transistor is coupled to the input terminal. The first current source is coupled to the input transistor and is configured to provide a bias current to the input transistor that is proportional to absolute temperature. The cascode transistor is coupled to the input transistor. The second current source is coupled to the cascode transistor and is configured to provide a bias current to the cascode transistor that is complementary to absolute temperature.
Claims16
An amplifier, comprising:
- an input transistor coupled to an input terminal;
- a first current source coupled to the input transistor, the first current source configured to provide a bias current to the input transistor that is proportional to absolute temperature;
- a cascode transistor coupled to the input transistor;
- and
- a second current source coupled to the cascode transistor, the second current source configured to provide a bias current to the cascode transistor that is complementary to absolute temperature;
- further comprising a diode connected transistor coupled to the cascode transistor and the second current source.
3 more elements
An amplifier, comprising:
- an input transistor coupled to an input terminal;
- a first current source coupled to the input transistor, the first current source configured to provide a bias current to the input transistor that is proportional to absolute temperature;
- a cascode transistor coupled to the input transistor;
- and
- a second current source coupled to the cascode transistor, the second current source configured to provide a bias current to the cascode transistor that is complementary to absolute temperature;
- wherein:
- the input transistor is a first input transistor;
- the input terminal is a first input terminal;
- and
- the amplifier further comprises a second input transistor coupled to a second input terminal and the first current source;
- wherein:
- the cascode transistor is a first cascode transistor;
- and
- the amplifier further comprises a second cascode transistor coupled to the second input transistor.
11 more elements
An amplifier, comprising:
- an input transistor coupled to an input terminal;
- a first current source coupled to the input transistor, the first current source configured to provide a bias current to the input transistor that is proportional to absolute temperature;
- a cascode transistor coupled to the input transistor;
- and
- a second current source coupled to the cascode transistor, the second current source configured to provide a bias current to the cascode transistor that is complementary to absolute temperature;
- wherein the second current source comprises:
- a third current source configured to generate a current that is proportional to absolute temperature;
- a bipolar transistor coupled to the third current source.
5 more elements
An amplifier, comprising:
- a first input terminal;
- a second input terminal;
- a first input transistor comprising a first terminal coupled to the first input terminal;
- a second input transistor comprising:
- a first terminal coupled to the second input terminal;
- and
- a second terminal coupled to a second terminal of the first input transistor;
- a first current source coupled to the second terminal of the second input transistor, and configured to provide a bias current to the first input transistor and the second input transistor that is proportional to absolute temperature;
- a first cascode transistor comprising a first terminal coupled to a third terminal of the first input transistor;
- a second cascode transistor comprising a first terminal coupled to a third terminal of the second input transistor;
- and
- a second current source coupled to the second cascode transistor, and configured to provide a bias current to the second cascode transistor that is complementary to absolute temperature;
- further comprising:
- a diode connected transistor comprising:
- a first terminal coupled to the second current source;
- and
- a second terminal coupled to the second current source, a second terminal of the first cascode transistor, and a second terminal of the second cascode transistor.
14 more elements
An amplifier, comprising:
- a first input terminal;
- a second input terminal;
- a first input transistor comprising a first terminal coupled to the first input terminal;
- a second input transistor comprising:
- a first terminal coupled to the second input terminal;
- and
- a second terminal coupled to a second terminal of the first input transistor;
- a first current source coupled to the second terminal of the second input transistor, and configured to provide a bias current to the first input transistor and the second input transistor that is proportional to absolute temperature;
- a first cascode transistor comprising a first terminal coupled to a third terminal of the first input transistor;
- a second cascode transistor comprising a first terminal coupled to a third terminal of the second input transistor;
- and
- a second current source coupled to the second cascode transistor, and configured to provide a bias current to the second cascode transistor that is complementary to absolute temperature;
- further comprising:
- a current mirror circuit comprising:
- a first transistor connected as a diode, and comprising a first terminal coupled to a second terminal of the first cascode transistor and a second terminal of the first transistor of the current mirror circuit;
- a second transistor comprising:
- a first terminal coupled to a second terminal of the second cascode transistor;
- and
- a second terminal coupled to the second terminal of the first transistor of the current mirror circuit.
16 more elements
An amplifier, comprising:
- a first input terminal;
- a second input terminal;
- a first input transistor comprising a first terminal coupled to the first input terminal;
- a second input transistor comprising:
- a first terminal coupled to the second input terminal;
- and
- a second terminal coupled to a second terminal of the first input transistor;
- a first current source coupled to the second terminal of the second input transistor, and configured to provide a bias current to the first input transistor and the second input transistor that is proportional to absolute temperature;
- a first cascode transistor comprising a first terminal coupled to a third terminal of the first input transistor;
- a second cascode transistor comprising a first terminal coupled to a third terminal of the second input transistor;
- and
- a second current source coupled to the second cascode transistor, and configured to provide a bias current to the second cascode transistor that is complementary to absolute temperature;
- further comprising a diode connected transistor comprising:
- a first terminal coupled to the second current source;
- and
- a second terminal coupled to a second terminal of the second cascode transistor and the second current source.
13 more elements
An amplifier, comprising:
- a first input terminal;
- a second input terminal;
- a first input transistor comprising a first terminal coupled to the first input terminal;
- a second input transistor comprising:
- a first terminal coupled to the second input terminal;
- and
- a second terminal coupled to a second terminal of the first input transistor;
- a first current source coupled to the second terminal of the second input transistor, and configured to provide a bias current to the first input transistor and the second input transistor that is proportional to absolute temperature;
- a first cascode transistor comprising a first terminal coupled to a third terminal of the first input transistor;
- a second cascode transistor comprising a first terminal coupled to a third terminal of the second input transistor;
- and
- a second current source coupled to the second cascode transistor, and configured to provide a bias current to the second cascode transistor that is complementary to absolute temperature;
- further comprising:
- a third current source coupled to the first cascode transistor, and configured to provide a bias current to the first cascode transistor that is complementary to absolute temperature;
- and
- a diode connected transistor comprising:
- a first terminal coupled to the third current source;
- and
- a second terminal coupled to a second terminal of the first cascode transistor and the second current source.
16 more elements
An amplifier input stage, comprising:
- a first input transistor and a second input transistor connected as a differential pair;
- a proportional to absolute temperature (PTAT) current source coupled to the first input transistor and the second input transistor, and configured to provide a bias current to the first input transistor and the second input transistor that is proportional to absolute temperature;
- a first cascode transistor coupled to the first input transistor;
- a second cascode transistor coupled to the second input transistor;
- and
- one or more complementary to absolute temperature (CTAT) current sources coupled to the first cascode transistor and the second cascode transistor, and configured to provide bias currents to the first cascode transistor and the second cascode transistor that are complementary to absolute temperature;
- further comprising:
- a diode connected transistor coupled to the first cascode transistor;
- wherein the one or more CTAT current sources comprises a first CTAT current source coupled to the diode connected transistor, and configured to provide a bias current to the first cascode transistor that is complementary to absolute temperature.
6 more elements
An amplifier input stage, comprising:
- a first input transistor and a second input transistor connected as a differential pair;
- a proportional to absolute temperature (PTAT) current source coupled to the first input transistor and the second input transistor, and configured to provide a bias current to the first input transistor and the second input transistor that is proportional to absolute temperature;
- a first cascode transistor coupled to the first input transistor;
- a second cascode transistor coupled to the second input transistor;
- and
- one or more complementary to absolute temperature (CTAT) current sources coupled to the first cascode transistor and the second cascode transistor, and configured to provide bias currents to the first cascode transistor and the second cascode transistor that are complementary to absolute temperature;
- wherein:
- the PTAT current source is a first PTAT current source;
- and
- the one or more CTAT current sources comprise:
- a bipolar transistor;
- and
- a second PTAT current source coupled to the bipolar transistor, and configured to provide a bias current to the bipolar transistor that is proportional to absolute temperature.
10 more elements
A method, comprising:
- supplying a first bias current that is proportional to absolute temperature to a cascode transistor of an input stage of an amplifier;
- trimming a power supply current of the amplifier while the supplying the first bias current;
- and
- disabling the first bias current and supplying a second bias current that is complementary to absolute temperature to the cascode transistor;
- wherein disabling the first bias current comprises opening a first fuse and supplying the second bias current comprises opening a second fuse.
2 more elements
Dependencies are inferred from the claim text.