| 摘要 |
PURPOSE:To eliminate the need for a D/A converter composed of a resistance network, and to facilitate integration, by performing A/D conversion through the charging and discharging of a capacitor. CONSTITUTION:The plus terminal of an integrator A composed of an operational amplifier 1 and a capacitor C3 is grounded, and its output is connected to the minus terminal of a comparator 2. The negative electrode of a reference voltage source 4 is connected to the minus terminal of the amplifier 1 through switches S1 and S2 and a capacitor C2. Further, a capacitor C1 grounded at one terminal is connected between the switches S1 and S2, and switches S3-S5 are connected in parallel to the capacitors C1 and C3. Input voltages applied to the plus terminal of the comparator 2 are converted successively into digital values by operating the switches S1-S5. Thus, the A/D conversion utilizes the charging and discharging of the capacitors, so the need for a D/A converter composed of a resistance network is eliminated, facilitating integration. |
