VOLTAGE CONTROLLED OSCILLATION CIRCUIT

摘要

PROBLEM TO BE SOLVED: To suppress the fluctuation of duty and to provide the oscillation output of a wide frequency range. SOLUTION: In this voltage controlled oscillation circuit, an oscillation basic circuit is constituted of a first inverter I1 and a PMOS clamp transistor NM3 connected between the first inverter and a power source Vss and a common oscillation frequency control terminal VR1 is connected to the gate of the transistor MN3. The oscillation basic circuit is chain-connected in a ring shape for odd-numbered stages, an amplifier circuit A1 composed of the plural stages of inverters is connected to the output terminal of one basic oscillation circuit and the output of the oscillation basic circuit is amplified stepwise to the signals of a sequentially higher level.