Voltage controlled oscillation circuit with plural voltage controlled current generating circuits

摘要

A voltage controlled oscillation circuit for use in a Phase Locked Loop circuit has a plurality of voltage controlled current generating circuits(60A,60B,60C), a current adder(62), and a current controlled oscillation circuit(70). Each of the voltage controlled current generating circuits has a control voltage-output current characteristic different from each other so as to stabilize a control voltage-oscillation frequency gain of the voltage controlled oscillation circuit against manufacturing variation of a voltage-current characteristic or a threshold voltage of transistors comprising said voltage controlled oscillation circuit.