| 摘要 |
PURPOSE:To prevent pulse noise from being generated, by providing a decoder circuit which suppresses the change of an X decode output at the minimum level, in all cases where data change by one bit. CONSTITUTION:In an X decoder 1 which uses the data D0-D2 on low-order sides out of input data D0-D5, an X decode signal having two outputs of two phases, a positive phase and a negative phase, is generated by using the input data of the least significant bit D3 on the high-order side of a Y decoder 2. Thereby, at the time of energizing/de-energizing constant current source fundamental circuits 0.0-7.7 with matrix structure, it is possible to prevent the output signals of the outputs X0-X7 of the decoder 1 from being changed simultaneously from H levels to L levels, or from the L levels to the H levels in all cases where the data to the X decoder 1 change. Therefore, it is possible to suppress noise on an analog signal due to a digital signal at the minimum level.
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