| 摘要 |
PURPOSE: To provide the high resolution and large dynamic range of a device by obtaining a value X from the time difference between respective reference points (a) and (b) of reference signals and the output signals of a controllable oscillator and the value Y from the difference of the number of the point (b) and the number of the point (b) at a prescribed reference moment. CONSTITUTION: A phase detector 1 samples the phase difference of the reference signals REF and the output signals OSC of the controllable oscillator 3 by the clocks of a frequency fA, quantizes it and codes it by Nf bits. Also, the detector 1 adds or subtracts '1' to/from a counter depending on whether or not the phase difference of both signals exceeds the positive or negative integral multiple of 2πand codes a state by Ng. A digital controller 2 processes the signals for which a circuit block 35 processes the Nf and Ng signals corresponding to a nonlinear characteristic curve, controls the oscillator 3 and constitutes a control loop. Thus, by the superimposing of fine and coarse quantization characteristic curves, this device of the high resolution and the large dynamic range is obtained. |
