| 摘要 |
<p>PURPOSE: To obtain a stable and simple circuit with a low cost and reduced noises which can be easily manufactured by connecting a transistor pair serially connected with a current source and a condenser with a clock, and selectively charging and discharging one of the capacitors in a shorter time than the time cycle of one cycle of a clock cycle. CONSTITUTION: This circuit is provided with a counter 10 which counts the number of level transitions, and a current source circuit 11 transmits a selected current level to a ratio circuit 12 in a selected time. The ratio circuit 12 uses two capacitors C1 and C2 , and each capacitor is serially connected with transistors Q1 and Q2 , and each capacitor and transistor pair is mutually connected in parallel between a control current source and earth. At least one transistor is turned off in the selected capacitor and transistor column, simultaneously the other capacitor and transistor column is directly controlled in a clock cycle, and the capacitor is charged and discharged. Thus, the stable and precise circuit with reduced noises and a low cost which can be easily manufactured can be obtained.</p> |
