| 摘要 |
PURPOSE:To efficiently convert a converting voltage into a digital value in a short time by discharging a capacitor till a reference voltage after the capacitor is charged up at high speed up to a high reference voltage and replacing the converted voltage into a digital value based on the time until the discharge voltage is coincident with the converted voltage from the discharge start point. CONSTITUTION:In switching the inside of a reference voltage generating section 12 so as to allow a voltage V3 to appear at a point R, a reference voltage VR is made stable at a voltage V3 at a point P3. Further, the section 12 is operated so that a reference voltage V2 lower by one stage appears at the point R and the time count and the supervision of a terminal O are started newly, then a capacitor 19 starts discharging up to a reference potential V2 through a voltage division resistor 16 to grasp a point P4 until the reference voltage VR is coincident again with the converting voltage VX and a time TX till the coincidence. The digital value of the converting voltage VX in this case is the subtraction of the difference between the basic digital value of the reference potential V3 and the basic digital value of the reference potential V2 being the proportional division by a discharge time T3 from the reference voltage V3 to the reference voltage V2 and the time TX' from the basic digital value of the reference voltage V3.
|
