Voltage controlled oscillation circuit having easily controllable oscillation characteristic and capable of generating high frequency and low frequency internal clocks

摘要

A current mirror circuit consisting of two P-channel MOS transistors in an operating current control section controls an operating current of a ring oscillator circuit in accordance with a current value of a constant current flowing in the current mirror circuit. A control voltage input section and a first current mirror resistance section in the operating current control section control the current value of the constant current generated by the current mirror circuit in accordance with a control voltage, and changes a range in which the constant current value is changed in response to a change of the control voltage, in accordance with a control signal.