| 摘要 |
PURPOSE:To improve conversion precision by carrying out the 3rd and 4th integral operations after double integration and then by performing the 4th integration with an integral time constant increased. CONSTITUTION:An analog voltage is inputted to the integrator for a certain time and after the 1st integration of T1 in time is performed, the 2nd integration is carried out by the input voltage and a reference voltage of the opposite polarity. The 2nd integration is performed for time T2 until the output potential of the analog integrator reaches ''0'' and during the operation, the counter counts clock pulses A. Next, the 3rd integration is carried out by the input voltage and the reference voltage of the same polarity for time T3. Next, the time constant of integer 4 is increased ten times and the clock of the counter is shifted down by one digit for counting. Further, the counting operation is interrupted for the time twice the 3rd integral time T3 in the 2nd integral time T2 so as to correct the counting. Thus, A/D conversion output H can be obtained. |
