| 摘要 |
PURPOSE:To obtain an A/D converter of a little error, by integrating a voltage corresponding to 1 LSB and storing a time required for discharging of the integrated voltage and integrating a voltage to be converted in this time and counting the frequency of discharging. CONSTITUTION:A voltage VLSB corresponding to 1 LSB is selected by a changeover switch S and is integrated by an integrator 2, and it is detected by a comparator 3 that the output of the integrator 2 reaches a voltage VA, and an input switching circuit 1 is switched by this output, and + and - of the input of the integrator 2 are switched, and electric charge integrated by the integrator 2 is discharged. The required time from the start of this integration to the end of discharging is stored. Next, the switch S is switched to repeat integration and discharging for the stored time similarly. When the frequency of this operation is counted, this count value is proportional to a voltage VS to be converted. |
