Stabilized noise shaper of a small scale having a suppressed quantization noise in high frequency region without deteriorating S/N ratio

DETAILED DESCRIPTION Accordingly, it is an object of the present invention to provide a noise shaper which has overcome the above mentioned defect of the conventional ones.
Another object of the present invention is to provide a noise shaper capable of suppressing the quantization noise shaped in the high frequency region without deteriorating the S/N characteristics so much, and capable of ensuring the system stability completely with a very small circuit scale.
The above and other objects of the present invention are achieved in accordance with the present invention by a noise shaper which comprises integrators of three or more stages, a quantizer and a feedback circuit, and which is characterized in that it comprises a means for subtracting from an output of each of the integrators a result obtained by delaying the output of the same integrator by one sample and multiplying it by a constant number, for outputting the result of the subtraction to an integrator at the subsequent stage, and a means for feeding back a result Obtained by delaying an output of the quantizer by one sample and multiplying it by any constant number value, to an input of each of the integrators.
The above and other objects, features and advantages of the present invention will be apparent from the following description of preferred embodiments of the invention with reference to the accompanying drawings.