| 摘要 |
A DELTA SIGMA digital/analog converter comprising an interpolator for sampling an input digital signal at a desired ratio, a noise-shaping coder for quantizing an output signal from the interpolator into the coded bits and modulating a quantization error generated in the quantization, a differentiator for detecting an intersignal variation from an output signal from the noise-shaping coder, the intersignal variation indicating a difference between previous and present digital signal values, a digital logic unit for generating a desired control signal according to the intersignal variation detected by the differentiator, an internal digital/analog converter for performing charging and discharging operations in response to the desired control signal from the digital logic unit to output an analog signal corresponding to the input digital signal, and a filter for filtering an output signal from the internal digital/analog converter to remove a mixed noise therefrom. According to the present invention, a minimized number of passive devices is used to reduce an error amount resulting from a process deviation, miniaturize a chip and easily enhance the internal bits without expanding the chip size.
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