SEMICONDUCTOR DEVICE, RADIO COMMUNICATION TERMINAL, AND SEMICONDUCTOR DEVICE CONTROL METHOD

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor device that comprises a PLL circuit able to suppress spurious noise generated on a particular channel.SOLUTION: According to an embodiment, a digital PLL circuit 1 comprises: a digital phase difference detector DPFD for detecting a phase difference between a reference oscillation signal Fref and a frequency-divided oscillation signal; a digital low-pass filter DLPF for outputting a digital code depending on a detection result of the digital phase difference detector DPFD; a digital control oscillator DCO for outputting an oscillation signal Fosc1 with a frequency corresponding to the digital code; a frequency dividing unit DIV1, MMD for frequency dividing and outputting the oscillation signal Fosc1 as a frequency-divided oscillation signal Fdiv; a noise strength detection unit FT1 for detecting the noise strength SL of a prescribed frequency component included in the digital code; and a phase difference adjusting unit CTL1 for adjusting the phase difference between the reference oscillation signal Fref and the frequency-divided oscillation signal Fdiv on the basis of a detection result of the noise strength detection unit FT1.