Title :
Improved wideband low distortion cascaded delta-sigma modulator
Author :
Yuan, Xiaolong ; Gothenberg, Andreas ; Wu, Xiaobo
Author_Institution :
KTH-ZJU Joint Res. Center of SoC, Zhejiang Univ., Hangzhou, China
Abstract :
It has recently become very popular to feedforward the input signal in wideband delta-sigma modulators, so that the integrators only process quantization errors. The advantage being that the actual signal is not distorted by opamp and integrator nonlinearities. In this paper, we focus on improved feedforward techniques for cascaded delta-sigma modulators. A feedforward cascaded structure is presented based on unity-gain signal transfer function (STF) and optimized noise transfer function (NTF) zero placement, using λ-analysis. The proposed structure has improved signal-to-noise-ratio (SNR) across the entire input range.
Keywords :
delta-sigma modulation; feedforward; transfer functions; cascaded delta-sigma modulator; feedforward cascaded structure; noise transfer function; quantization error; signal transfer function; signal-to-noise-ratio; wideband delta-sigma modulator; Circuits; Delta modulation; Noise reduction; Noise shaping; Quantization; Signal processing; Signal to noise ratio; Transfer functions; Voltage; Wideband;
Conference_Titel :
System-on-Chip for Real-Time Applications, 2005. Proceedings. Fifth International Workshop on
Print_ISBN :
0-7695-2403-6
DOI :
10.1109/IWSOC.2005.75
