| 摘要 |
PURPOSE:To provide the control circuit to compensate a characteristic such as a temperature fluctuation of a VCO connected to a next stage with less number of components with respect to a signal adder circuit in a double loop PLL. CONSTITUTION:The control circuit is provided with a current mirror circuit 6 controlled by transistors (TRs) having the same characteristic as that of TRs being components of a VCO connecting to a next stage, and an output current of the current mirror circuit controls a current of differential amplifier circuits 7,9, output currents of the two sets of the differential amplifier circuits 7,9 are added by a current adder circuit 8 and a current mirror circuit 10 supplies the current to a resistor R3 and an output voltage is extracted from a prescribed location of the resistor R3. |
