FREQUENCY VARIABLE OSCILLATION CIRCUIT, PHASE SYNCHRONIZING CIRCUIT AND CLOCK SYNCHRONIZING CIRCUIT USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a frequency variable oscillation circuit which is capable of operating with a low power supply voltage and oscillating at a high frequency, and a phase synchronizing circuit and clock synchronizing circuit having a wide oscillation frequency range using the same.;SOLUTION: A positive feedback circuit is configured by mutually cross-connecting a differential amplifier circuit and an input/output terminal using a complementary amplifier circuit mutually connecting gates of pMOS and nMOS transistors as an input terminal and mutually connecting their drains as an output terminal. The positive feedback circuit is connected between output terminals of the differential amplifier circuit. A delay circuit is configured by serially connecting, between a power supply terminal and a ground terminal, an MOS transistor, in which a frequency control signal for controlling a source current of the complementary amplifier circuit is inputted to its gate, and the complementary amplifier circuit. Such delay circuits are annularly cascaded to configure a frequency variable oscillation circuit.;COPYRIGHT: (C)2006,JPO&NCIPI