| 摘要 |
PURPOSE:To make a low-precision DAC (digital-analog converter) high-precision to use it by combining a DAC having an ordinary precision and one or more current sources and storing and correcting the nonlinear error of the DAC with operations of digital elements such as a counter and a register and an auxiliary DAC. CONSTITUTION:One ends of current sources 21, 22 -23, and 24 are connected to a switch circuit 35 through switch circuits 31', 32'-33', and 34' in a switch circuit part 30', and the other ends are connected to a power supply terminal 200 to which a prescribed constant voltage is applied. The switch circuit 35 is connected to the side of a terminal (b) to supply the output current of the current source, which is selected by the switch circuit part 30', to a current-voltage coverter 3 in case of the correction mode; and in case of the conversion mode, the switch circuit 35 is connected to the side of a terminal (a), and an output current corresponding to upper m-number of bits is taken out from an output terminal 101 together with the output current of a DAC 1 (which is not shown in Fig.) corresponding to lower n-number of bits. |
