| 摘要 |
<p>A semiconductor device according to an embodiment comprises: a phase comparator which generates phase difference determination signals (UP, DN); control current generation circuits (211-21m) each of which is provided with a current source for generating a first bias current having a predetermined current value, and inputs/outputs a frequency control current generated from the first bias current on the basis of the phase difference determination signals (UP, DN); a loop filter (26) which generates frequency control voltage on the basis of the frequency control current; a voltage control oscillator (27) which controls the frequency of an output signal (S3) according to the frequency control voltage; and a control unit (109) which generates a parallel number switching signal (S1) and a bias current switching signal (S2). Regarding the control current generation circuits (211-21m), the number of control current generation circuits which operate in parallel in response to the parallel number switching signal (S1) is controlled, and the frequency control current inputted/outputted by one control current generation circuit in response to the bias current switching signal (S2) is set to the reciprocal multiple of a parallel number.</p> |
