SEMICONDUCTOR INTEGRATED CIRCUIT FOR USE IN COMMUNICATION AND MOBILE COMMUNICATION TERMINAL

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor integrated circuit (high frequency IC) for use in communication capable of detecting variations a loop gain of an amplitude control loop and correcting a loop band of a transmission circuit including a phase control loop and an amplitude control loop without the need for using an external measurement device. SOLUTION: The semiconductor integrated circuit (high frequency IC) for use of communication provided with a transmission circuit including the phase control loop controlling a phase of a carrier and the amplitude control loop controlling the amplitude of a transmission output signal, includes a calibration circuit (140) for detecting variations in a loop gain of the amplitude control loop to correct the loop band. The calibration circuit is configured such that an electric parameter of any circuit on the amplitude control loop is stepwise changed and variations in the loop gain are detected by comparing a feedback signal at that time with an output signal of a modulation circuit (111) and the characteristic of any circuit on the amplitude control loop is changed in response to the detected variations to correct the loop band. COPYRIGHT: (C)2007,JPO&INPIT