| 摘要 |
PURPOSE:To form a reference amount for A/D conversion wit high accuracy without being affected with the capacitance difference of capacitors by changing over alternately the capacitor for discharge reset and the capacitor leading the output at each bit. CONSTITUTION:A switch 1 is provided to charge the capacitors C1, C2 connected in series. Further, switches 8,9 are used for discharging the capacitor C1 and switches 9,10 are used for discharging the capacitor C2 respectively. Moreover, the charge distribution to the capacitors C1, C2 is conducted by the switches 8,9. The switches 1 and 8-10 are subjected to on/off control by control signals A,B-D generated from a control circuit 11. Then potential differences v01, v02 across the capacitors C1, C2 are sampled and led by a sample and hold circuit and used for the reference amount of each bit. |
