Bias circuit with mode control and compensation for voltage and temperature
AssigneeTriQuint Semiconductor, Inc.
InventorsThomas Apel, Rebouh Benelbar
Life of this patent
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Abstract
An amplifier bias system. The amplifier bias system includes a battery voltage supply coupled with an amplifier transistor to be biased; an output node coupled with a gate of the amplifier transistor; and a current source coupled with the battery voltage supply, wherein the current source provides a current to a node in response to the battery voltage supply. The amplifier bias system further includes a first transistor coupled between the battery voltage supply and the output node, the first transistor having a gate coupled with the first node; a second transistor coupled with the first node, the second transistor having a gate coupled with the output node; and a current load coupled with the output node.
Claims14
An amplifier bias system comprising:
- a battery voltage supply coupled with an amplifier transistor to be biased;
- an output node coupled with a gate of the amplifier transistor;
- a current source coupled with the battery voltage supply, wherein the current source provides a first current to a first node in response to the battery voltage supply;
- a first transistor coupled between the battery voltage supply and the output node, the first transistor having a gate coupled with the first node;
- a second transistor coupled with the first node, the second transistor having a gate coupled with the output node;
- and
- a current load coupled with the output node.
The amplifier bias system of Claim I, further comprising a voltage compensation circuit coupled with the battery voltage supply and the first node, wherein the voltage compensation circuit is configured to reduce a current flowing through the second transistor as a battery voltage provided by the battery voltage supply increases.
A method of biasing an amplifier transistor comprising:
- generating a control current that varies linearly with respect to variations in a battery supply voltage;
- adjusting the control current in response to variations in the battery supply voltage;
- adjusting the control current in response to variations in temperature;
- and
- mirroring the control current to the amplifier transistor.
Dependencies are inferred from the claim text.