Digital .SIGMA.-.DELTA. modulator

A digital .SIGMA.-.DELTA. modulator comprising:

• input means for sequentially receiving a digital signal of one channel from digital signals of n (n is an integer of not less than 2) channels in response to a clock signal, the digital signal having k (k is an integer of not less than 3) bits;
• m subtracting means each for subtracting a feedback signal from the digital signal of one channel input from said input means;
• m integrating means, connected to said m subtracting means, for integrating signals output from said m subtracting means, respectively;
• quantizing means, connected to said mth integrating means, for quantizing a signal output from said integrating means into a quantized value j (j is an integer falling within a range of 1<j<2.sup.K) and generating an output signal;
• delay means, connected to said quantizing means, for delaying the output signal from said quantizing means by n clocks and generating the feedback signal;
• and
• output means, connected to said quantizing means, for assigning the signal output from said quantizing means to n channels in accordance with the given order of the signals input by said input means, and outputting the signal.

A digital .SIGMA.-.DELTA. modulator comprising:

• input means for sequentially receiving digital signals of two channels in units of channels;
• first subtracting means, connected to said input means, for subtracting a feedback signal from the signal of one channel input by said input means;
• first delay means, connected to said first subtracting means, for delaying a signal output from said first subtracting means;
• adding means, connected to said first delay means, for adding the feedback signal to a signal output from said first delay means;
• quantizing means, connected to said adding means, for quantizing a signal output from said adding means;
• second subtracting means, connected to said adding means and said quantizing means, for subtracting a signal output from said quantizing means from a signal output from said adding means;
• second delay means, connected to said second subtracting means, for delaying a signal output from said second subtracting means and outputting the feedback signal;
• and
• output means, connected to said quantizing means, for, assigning the output from said quantizing means to 2 channels in accordance with an input order in said input means.

A digital .SIGMA.-.DELTA. modulator comprising:

• input means for dividing an n-bit (n is an integer of not less than 2) digital signal into i (i is an integer of not less than 2;
• i<n) signals and sequentially inputting the divided digital signals from an LSB side;
• subtracting means, connected to said input means, for subtracting a feedback signal from the digital signal input by said input means;
• integrating means, connected to said subtracting means, for integrating a signal output from said subtracting means i times;
• quantizing means, connected to said integrating means, for quantizing a signal output from said integrating means and generating an output signal;
• delay means, connected to said quantizing means, for delaying the output signal from said quantizing means by i clocks and generating the feedback signal;
• and
• output means, connected to said quantizing means, for outputting the output signal output from said quantizing means.