| 摘要 |
PURPOSE:To reduce the cost of monolithic manufacture by obtaining a resistance network of high precision by the process of monolithic manufacture by forming the 1st-n-th groups of resistors by selectively connecting one resistance element of each row and each column together by metal wiring without fail. CONSTITUTION:Eight groups of resistors are formed of eight-row by eight-column resistance elements r11-R88; seven groups of resistors are used as R-2R radar circuits, and one group of them as a feedback resistor. Then, the basic constitution of a transfer switch as an electronic switch composed of two FETs and an inverter composed of two FETs as well is employed to obtain a digital-analog converter with two-bit input. For eight-bit input, twenty five groups of resistors as R-2R resistors and one group of feedback resistance are combined in a twenty-six row by twenty-six column matrix of resistance elements. Consequently, the manufacture cost can be reduced without deteriorating the digital-analog converting function and characteristics. |
