| 摘要 |
PURPOSE:To enhance the signal accuracy in the linking part, to improve a high accuracy, to decrease the number of bits at the electric current dividing system side and to lower the electric power source voltage by providing an electric current correcting means at the linking part in the DA converter to assemble the electric current dividing system and an R-2R RADA system. CONSTITUTION:An R-2R RADA system digital analog converting part 2 which goes to be the converting part of lower order side bits D0-D4, and an electric current dividing system digital analog converting part 1 which goes to be the electric current source of the converting part 2 and the converting part of higher order side bits D5-D8 are linked by a connection P. To the linking part, an electric current source ISE for correction, an electric current dividing device 18 and a transistor TrA for correction are added as an electric current corresponding means, and out of electric currents to flow from an R-2R RADA system DA converting part 2 to an electric current dividing system DA converting part 1, an electric current I0 of the value equal to the sum of the base electric current of respective transistors of the converting part 2 is pulled out as a correcting electric current. Thus, the electric current accuracy of the connecting point is enhanced. Namely, the electric current to flow to the electric current dividing system DA converting part, goes to be the value very close to the output electric current value of all bits of the R-2R RADA system DA converter.
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