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US 8,149,056 B2Granted
Amplifying circuit
AssigneeSTMicroelectronics (Grenoble) SAS
InventorsSerge Pontarollo, Serge Ramet
Life of this patent
Estimating the term…
Abstract
An amplifier having an output stage with a complementary pair of first and second transistors each coupled to an output node of the amplifier; control circuitry arranged to provide a control signal at a control node of the first transistor based on the voltage at an input node of the amplifier; and adjustment circuitry arranged to adjust the control signal to maintain the current through the first transistor above a minimum value.
Claims33
An amplifier comprising:
- an output stage comprising a complementary pair of first and second transistors each coupled to an output node of the amplifier;
- control circuitry arranged to provide a control signal at a control node of said first transistor based on the voltage at an input node of said amplifier;
- and
- adjustment circuitry comprising a first fixed current source and arranged to adjust said control signal to increase the current through said first transistor responsive to the current through said first transistor falling below a minimum value.
1 more element
A device comprising:
- an output stage of an amplifier comprising a complementary pair of first and second transistors each coupled to an output node of the amplifier;
- and
- means for adjusting, comprising a first fixed current source, a first control signal at a first control node of the first transistor to increase the current through the first transistor responsive to the current through the first transistor falling below a selected minimum value.
A method of amplifying a signal, the method comprising:
- receiving a first control signal at a first control terminal of a first transistor in an output stage of an amplifier, the first control signal based upon an input signal level applied to an input node of the amplifier and the first transistor configured to drive current at an output node of the amplifier;
- detecting whether current through the first transistor falls below a selected minimum value;
- and
- adjusting the first control signal to increase current through the first transistor responsive to detecting that the current through the first transistor falls below the minimum value,
- wherein the adjusting is dependent upon an amount of current delivered to a constant current source.
2 more elements
Dependencies are inferred from the claim text.