Patent ID: 6842486

Claim:
A digital to analog converter system, comprising: a digital to analog converter (“DAC”) to (i) receive a digital input signal, sampled at frequency f S and having frequency components primarily within a frequency baseband, and out of baseband noise and to (ii) convert the digital input signal into a representative analog signal, the DAC comprising: a modulation circuit having a modulation frequency of approximately or equal to f S /2 to modulate the digital input signal by approximately or equal to f S /2; a gain stage coupled to the modulation circuit to receive signals modulated by the modulation circuit and provide gain for the DAC, wherein during operation the gain stage is associated with noise having frequencies within the baseband; and a demodulation circuit, coupled to the gain stage and having a demodulation frequency equal to approximately or equal to f S /2, to demodulate signals and allow frequency components of the input signal to fold back into the baseband, to reduce fold back into the baseband of the quantization noise frequency components, and modulate the noise associated with the gain stage substantially out of the baseband.