Skyworks Solutions, Inc.

Youngoo Yang

Kevin Choi

Nai-Shuo Cheng

Bong-Seok Park

A bias control circuit for controlling a bias circuit coupled to an amplifier transistor. The bias control circuit receives a control voltage, and actively adjusts an equivalent resistance of the bias control circuit responsive to the control voltage, wherein the equivalent resistance is established between a first node and a reference voltage. In one embodiment, when the control voltage is increased, the equivalent resistance is gradually decreased and a current drawn by the bias control circuit is gradually increased, resulting in a quiescent current of the amplifier transistor being gradually increased.

Quiescent current control circuit for high-power amplifiers

An exemplary bias circuit is coupled to an amplifier. The bias circuit comprises a first bipolar transistor, a second bipolar transistor and a third bipolar transistor. The first bipolar transistor has a base connected to a first node, and the first node is connected to a reference voltage through a first resistor. The second bipolar transistor has a base connected to the first node. The third bipolar transistor has a collector connected to the first node and a base connected to an emitter of the first bipolar transistor at a second node. An emitter of the second bipolar transistor is connected to a base of a fourth bipolar transistor associated with the amplifier, and the second bipolar transistor does not have a resistor connected to the emitter of the second bipolar transistor.

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Thousand Oaks, CA, United States of America

Youngoo Yang