A 200 KHz bandwidth ΣΔ DAC with a spur free modulator

This paper creatively presents a sigma-delta digital to analog converter (ΣΔDAC) which achieves 88.5 dB signal to noise and distortion ratio (SNDR) in the 200 KHz bandwidth. The proposed modulator with a high pass dither block can eliminate harmonic spurs without increasing the noise floor in band. In addition, a 2nd-order vector feedback dynamic element match (VFBDEM) provides a good harmonic suppression via mismatch noise shaping. What's more, the cut-off frequency of the proposed modified model of the 1st-order low-pass SC DAC is accordance with that of ΣΔDAC, consequently, filtering out high frequency noise to alleviate the SNDR decrease caused by clock jitter.