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US 5,568,090 AGranted
Amplifier circuit with dynamic output stage biasing
AssigneeElantec, Inc.
InventorJoseph R. Pierret
Life of this patent
Estimating the term…
Abstract
An amplifier circuit is disclosed having circuitry that senses an electrical current at the output node while dynamically adjusting a bias current for an output circuit of the amplifier circuit. The bias current controls the amount of electrical current that the output circuit sinks or sources at the output node.
Claims19
An amplifier circuit, comprising:
- gain stage having a current mirror load circuit including a first transistor with a base coupled to a base of a second transistor and including a first resistor coupled to the emitters of each of the first and second transistors;
- circuit that generates an output bias electrical current in response to the voltage on the bases of the first and second transistors;
- output stage having an output transistor biased by the output bias electrical current and having a circuit that senses an output current at an output node and that feeds back a portion of the output current to the first resistor such that the portion of the output current adjusts the voltage on the bases of the first and second transistors in the current mirror load circuit.
An amplifier circuit, comprising:
- gain stage having a current mirror load circuit including a first transistor with a base coupled to a base of a second transistor and including a first resister coupled to the emitters of each of the first and second transistors;
- output stage having a circuit that generates an output bias electrical current in response to the voltage on the bases of the first and second transistors and having and output transistor that sinks an output current at an output node and that is biased by the output bias electrical current, the output stage having a feedback current that senses the output current and that feeds back a portion of the output current to the first resister such that the portion of the output current adjusts the voltage on the bases of the first and second transistors.
An amplifier circuit, comprising:
- gain stage having a current mirror load circuit including a first transistor with a base coupled to a base of a second transistor and including a first resister coupled to the emitters of each of the first and second transistors;
- output stage having a circuit that generates an output bias electrical current in response to the voltage on the bases of the first and second transistors and having an output transistor that sources an output current at an output mode and that is biased by the output bias electrical current, the output stage having a feedback circuit that senses the output current and that feeds back a portion of the output current to the first resister such that the potion of the output current adjusts the voltage on the bases of the first and second transistors.
Dependencies are inferred from the claim text.