NOISE ATTENUATION CIRCUIT FOR DATA CONVERTER, AND METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To obtain a sigma-delta converter that reduces or excludes an undesired tone in a pass band caused by a pattern noise. SOLUTION: This method is the method to attenuate a noise in an output signal produced by this data converter 10. The data converter 10 is provided with a sigma-delta modulator 16, a D/A converter 17, a clock generator 19 connected to the D/A converter 17, and a clock control circuit 18 connected to the clock generator 19. The clock control circuit 18 activates or deactivates the clock generator in response to a single bit digital signal so as to cause a notch characteristic in the output signal thereby attenuating a nose in the output signal.