Multi-stage noise shaping over-sampling D/A converter

Claim 2

An over-sampling digital-to-analog converter comprising: a noise shaping quantization circuit coupled to receive a digital signal as input, for producing a quantized output signal; and a digital-to-analog conversion circuit for converting said quantized output signal to an analog signal; wherein said noise shaping quantization circuit has final quantization levels of -L, -(L-1), ...., -1, 0, +1, ......, +(L-1), +L , where L is a positive integer.

Claim 3

An over-sampling digital-to-analog converter according to claim 1, in which said noise shaping quantization circuit comprises: a single-integration noise shaping quantization circuit coupled to receive said input digital signal; a double-integration noise shaping quantization circuit coupled to receive a quantization error signal produced from said single-integration noise shaping quantization circuit; differentiator means for differentiating an output signal produced from said double-integration noise shaping quantization circuit; and adder means for summing an output signal produced from said differentiator means and an output signal produced from said single-integration noise shaping quantization circuit; wherein said digital-to-analog conversion circuit converts a sum output signal produced from said adder means to an analog signal, and wherein said single-integration noise shaping quantization circuit has quantization levels of -N, -(N-1), ...., -1, 0, +1, ......, + (N-1), +N where N is a positive integer, and said double integration noise shaping quantization circuit has quantization levels of -M, -(M-1), ....., -1, 0, +1,...., +(M-1), +M where M is a positive integer which is lesser than N

Claim 4

An over-sampling digital-to-analog converter according to claim 1 in which said noise shaping quantization circuit comprises: a first single-integration noise shaping quantization circuit coupled to receive said input digital signal; a second single-integration noise shaping quantization circuit coupled to receive a quantization error signal produced from said first single integration noise shaping quantization circuit; differentiator means for differentiating an output signal produced from said second single integration noise shaping quantization circuit; and adder means for summing an output signal produced from said differentiator means and an output signal produced from said first single-integration noise shaping quantization circuit; wherein said digital-to-analog conversion circuit converts a sum output signal produced from said adder means to an analog signal, and wherein said first single-integration noise shaping quantization circuit has quantization levels of -N, -(N-1), ...., -1, 0, +1, ......, +(N-1), +N where N is a positive integer.

Claim 5

An over-sampling digital-to-analog converter according to claim 1 in which said noise shaping quantization circuit comprises: a first double-integration noise shaping quantization circuit coupled to receive said input digital signal; a second double-integration noise shaping quantization circuit coupled to receive a quantization error signal produced from said first double integration noise shaping quantization circuit; differentiator means for second order differentiating an output signal produced from said second double integration noise shaping quantization circuit; and adder means for summing an output signal produced from said differentiator means and an output signal produced from said first double-integration noise shaping quantization circuit; wherein said digital-to-analog conversion circuit converts a sum output signal produced from said adder means to an analog signal, and wherein said first double-integration noise shaping quantization circuit has quantization levels of -N, -(N-1), ...., -1, 0, +1, ......, +(N-1), +N where N is a positive integer.

Claim 6

An over-sampling digital-to-analog converter comprising: a single-integration noise shaping quantization circuit coupled to receive a digital input signal; a double-integration noise shaping quantization circuit coupled to receive a quantization error signal produced from said single-integration noise shaping quantization circuit; differentiator means for differentiating an output signal produced from said double-integration noise shaping quantization circuit; and adder means for summing an output signal produced from said differentiator means and an output signal produced from said single-integration noise shaping quantization circuit; wherein said digital-to-analog conversion circuit converts a sum output signal produced from said adder means to an analog signal, and wherein said single integration noise shaping quantization circuit has quantization levels of -N, -(N-1), ...., -1, 0, +1, ......, +(N-1), +N where N is a positive integer.

Claim 7

An over-sampling digital-to-analog converter comprising: a single-integration noise shaping quantization circuit coupled to receive a digital input signal; a double-integration noise shaping quantization circuit coupled to receive a quantization error signal produced from said single-integration noise shaping quantization circuit; differentiator means for differentiating an output signal produced from said double-integration noise shaping quantization circuit; and adder means for summing an output signal produced from said differentiator means and an output signal produced from said single-integration noise shaping quantization circuit; wherein said digital-to-analog conversion circuit converts a sum output signal produced from said adder means to an analog signal, and wherein said single integration noise shaping quantization circuit has quantization levels of -N, -(N-1), ...., -1, 0, +1, ......, +(N-1), +N where N is a positive integer.

Claim 8

An over-sampling digital-to-analog converter comprising: a single-integration noise shaping quantization circuit coupled to receive a digital input signal; a double-integration noise shaping quantization circuit coupled to receive a quantization error signal produced from said single-integration noise shaping quantization circuit; differentiator means for differentiating an output signal produced from said double-integration noise shaping quantization circuit; and adder means for summing an output signal produced from said differentiator means and an output signal produced from said single-integration noise shaping quantization circuit; wherein said digital-to-analog conversion circuit converts a sum output signal produced from said adder means to an analog signal, and wherein said single integration noise shaping quantization circuit has quantization levels of -3N, -2N, -1N, 0, +1N, +2N, +3N, where N is a positive integer.

Claim 9

An over-sampling digital-to-analog converter comprising: a single-integration noise shaping quantization circuit coupled to receive a digital input signal; a double-integration noise shaping quantization circuit coupled to receive a quantization error signal produced from said single-integration noise shaping quantization circuit; differentiator means for differentiating an output signal produced from said double-integration noise shaping quantization circuit; and adder means for summing an output signal produced from said differentiator means and an output signal produced from said single-integration noise shaping quantization circuit; wherein said digital-to-analog conversion circuit converts a sum output signal produced from said adder means to an analog signal, and wherein said single integration noise shaping quantization circuit has quantization levels of -3N, -2N, -1N, 0, +1N, +2N, +3N, where N is a positive integer.

Claim 10

An over-sampling digital-to-analog converter comprising: a single-integration noise shaping quantization circuit coupled to receive a digital input signal; a double-integration noise shaping quantization circuit coupled to receive a quantization error signal produced from said single-integration noise shaping quantization circuit; differentiator means for differentiating an output signal produced from said double-integration noise shaping quantization circuit; and adder means for summing an output signal produced from said differentiator means and an output signal produced from said single-integration noise shaping quantization circuit; wherein said digital-to-analog conversion circuit converts a sum output signal produced from said adder means to an analog signal, wherein said single integration noise shaping quantization circuit has quantization levels of -3, -2, -1, 0, +1, +2, +3, and wherein a minimum positive threshold value Y for quantization of said input digital signal by said single-integration noise shaping quantization circuit is established as R/6, where R is an integral multiple of 6 and is greater than a maximum positive value with respect to zero of said input digital signal, and in which threshold values of said single-integration noise shaping quantization circuit feedback signal respectively corresponding to said quantization levels of said single-integration noise shaping quantization circuit are established as -5Y, -3Y, -Y, +Y, +3Y, +5Y, and moreover in which feedback signal levels of said noise shaping quantization circuit respectively corresponding to said quantization levels of said single-integration noise shaping quantization circuit are established as -6Y, -4Y, -2Y, 0, +2Y, +4Y, +6Y.

Claim 11

An over-sampling digital-to-analog converter comprising: a single-integration noise shaping quantization circuit coupled to receive a digital input signal; a double-integration noise shaping quantization circuit coupled to receive a quantization error signal produced from said single-integration noise shaping quantization circuit; differentiator means for differentiating an output signal produced from said double-integration noise shaping quantization circuit; and adder means for summing an output signal produced from said differentiator means and an output signal produced from said single-integration noise shaping quantization circuit; wherein said digital-to-analog conversion circuit converts a sum output signal produced from said adder means to an analog signal, wherein said single integration noise shaping quantization circuit has quantization levels of -3, -2, -1, 0, +1, +2, +3, and wherein a minimum positive threshold value Y for quantization of said input digital signal by said single-integration noise shaping quantization circuit is established as R/6, where R is an integral multiple of 6 and is greater than a maximum positive value with respect to zero of said input digital signal, and in which threshold values of said single-integration noise shaping quantization circuit feedback signal respectively corresponding to said quantization levels of said single-integration noise shaping quantization circuit are established as -5Y, -3Y, -Y, +Y, +3Y, +5Y, and moreover in which feedback signal levels of said noise shaping quantization circuit respectively corresponding to said quantization levels of said single-integration noise shaping quantization circuit are established as -6Y, -4Y, -2Y, 0, +2Y, +4Y, +6Y.

Claim 12

An over-sampling digital-to-analog converter according to claim 7, in which said double-integration noise shaping quantization circuit has quantization levels of -1, 0 and +1.