| 摘要 |
PURPOSE:To simplify the constitution of the titled circuit, by dividing the reference voltage to be compared with a power supply voltage through a comparator into a nonlinear ratio, then performing the subsequent processes in a linearized form. CONSTITUTION:A reference voltage dividing circuit 12 consists of a series connected substance of resistances R11-R14 and R15 and divides the reference voltage Vr to be applied to a reference voltage input terminal 13 to deliver the voltages (1/1.414)Vr, (1/1.732)Vr, (1/2)Vr and (1/2.236)Vr to points C1-C4 respectively. These output voltages are compared with the power supply voltage V0 supplied from a terminal 11 through each unit comparator of a comparing circuit 14. The outputs d1-d4 are set at logic value 1 when the V0 is higher than the output voltage and at logic value 0 when the V0 is lower than the output voltages respectively. Thus the contents of a shift register 15 is decided. Then a voltage supply time width deciding circuit 17 detects the contents of the register 15, and the supply voltage is controlled. |
