| 摘要 |
PURPOSE:To save the consumption of a power and prolong the lifetime of a power souce by a method wherein a voltage obtained by lowering a supply voltage is supplied to a circuit whose operation frequency is relatively high. CONSTITUTION:An oscillation signal P1 is supplied to a frequency divider 2, a frequency-division signal P3 is shaped 4, and a sampling signal P4 is supplied to a voltage level detecting circuit 5, while a signal P5 for counting is supplied to a counter 6 for control. The circuit 5 discriminates the amplitude of a voltage- division signal P6 according to the fall of the signal P4 and delivers it as a signal P7. The signal P7 controls the counter 6 to make the signal P5 perform up/ down counting, and according to the state of output of count signals S1-S3 thus obtained, an adjusting circuit 7 delivers a frequency-division signal P2 as a signal P8 having a different pulse width. The signal P8 is averaged 8 to a voltage signal P9, which changes the on-resistance of a power amplifying circuit 9 as a means for lowering a voltage which is constituted by MOSFET. As the result, an output potential VSS1 is controlled, and it is supplied to an oscillation circuit 1, a frequency-dividing circuit 2, etc. |
