| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply circuit capable of reducing the current consumption of the circuit itself and optimizing the consumption of a current flowing into a load in accordance with the variation of current consumption when the current consumption is sharply changed in accordance with a difference between the operation states of a load such as a VCO circuit. SOLUTION: When the input control voltage of a VCO circuit 14 is low, oscillation frequency is reduced and the current consumption of the VCO circuit 14 is small. Thereby the output of a comparator 13 is turned to an 'L' level and a sub-regulator 12 does not supply power to the VCO circuit 14, which is driven only by a main regulator 11. When the input control voltage of the VCO circuit 14 is high, the oscillation frequency is increased and the current consumption of the VCO circuit is large. Thereby the output of the comparator 13 is turned to 'H' and the sub-regulator 12 supplies power to the VCO circuit 14, so that the VCO circuit 14 can be driven by both the regulators 11, 12. |
