| 摘要 |
PURPOSE:To improve the resolution without being affected with the error of element, by splitting a capacitance of weighting corresponding to high-order bits into plural capacitances to prevent the monotonous increase from being lost due by the error in weighted capacitance. CONSTITUTION:A voltage between the 1st and 2nd voltages V1, V2 is divided with the capacitance to obtain an output voltage V0. Changeover switches SW1- SW9 connect one end of weighted capacitors C0-8C0 and 16C0 (1)-(3) to the V1 or V2 in response to the input digital signal. A transistor TD charges up each capacitance to a prescribed potential prior to the voltage division and is turned on for a short time with a clock CLK. A gate circuit having an OR gate OG1 and an AND gate AG1 is used to control the switches SW6-SW9. |
