| 摘要 |
PROBLEM TO BE SOLVED: To make a switching circuit for a capacitor for correction switchable easily in response to an external signal and a loss caused by insertion of the switching circuit restrainable. SOLUTION: A semi-conductor switch 100 for the capacitor CS for the correction for correcting an electrostatic capacity of an LC resonance circuit is constituted of an N-channel MOS type FET1, and a gate of the FET1 is connected to an anode of a diode D1. A cathode of the diode D1 is connected to a drain of the second FET2 constituting an input circuit 200. The FET2 is imparted with a signal from an input terminal 9 to be turned on and off, so as to control a voltage applied to the cathode of the diode D1. COPYRIGHT: (C)2003,JPO |
