The present disclosure relates to a power amplifier circuit. The power amplifier circuit includes a voltage-controlled current source and a current mirror. The voltage-controlled current source is configured to receive a first voltage and to generate a first current. The current mirror is connected to the voltage-controlled current source and to generate a second current in response to the first current. The second current continuously changes from 0 mA to about 120 mA as the first voltage continuously changes from 0 V to about 1 V.