Amplifying device with bias timing control circuit based on duty cycle

Abstract

A bias timing control circuit includes a current source, a bias switch circuit, a duty cycle sensing circuit, and a switching control circuit. The bias switch circuit includes a first path switch, connected between an output node of the current source and a bias amplifying circuit, and a second path switch, connected between the output node of the current source and a temperature compensation circuit. The duty cycle sensing circuit is configured to generate a timing control signal based on a duty cycle of a transmission enable signal. The switching control circuit is configured to control a first turn-on time of the first path switch during an initial startup period, and a second turn-on time of the second path switch during a normal driving period subsequent to the initial startup period to adjust a warm-up time of a power amplifying circuit based on the timing control signal.