| 摘要 |
PURPOSE:To obtain a current output with high accuracy even when a current source with bad accuracy is used by selecting one of (2<m>+1) of current sources having an identical current value at every other prescribed time, passing its output to an LPF as the 1st current output, passing the output of the remaining current source through the LPF as the 2nd current output. CONSTITUTION:A current switching circuit 1 selects one current source in order at every other prescribed time from a current source group comprised of (2<m>+1) sets of current sources having the identical current value by a control signal 10. The output current 19 from the selected current source has a fluctuation due to the variance in the current source, but the fluctuation passes through an LPF 3 to obtain an averaged current output 8'. Further, the output current 20 added with the output current from the remaining 2<m> sets of current sources has a fluctuation at the same time as well, the current 20 passes through the LPF 3, is averaged to form a current output 9'. The output currents 8', 9' are processed as conventionally and an analog 12 corresponding to a digital signal 11 is obtained.
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