Title :
A novel highly stable multiple-feedback oversampled lowpass Σ-Δ A/D converter configuration
Author :
Fraser, Neil A. ; Nowrouzian, Behrouz
Author_Institution :
Dept. of Electr. & Comput. Eng., Alberta Univ., Edmonton, Alta., Canada
Abstract :
The existing multiple-feedback Σ-Δ A/D converters usually feature, (a) complementary signal and noise transfer functions, and/or (b) unit-circle noise transfer function zeros. However, in corresponding switched-capacitor (SC) hardware implementations, such A/D converters may become prone to instability as a result of capacitor mismatches. This paper is concerned with the development of a novel multiple-feedback lowpass Σ-Δ A/D converter having, instead, magnitude-squared or magnitude complementary signal and noise transfer functions. The proposed A/D converter offers increased stability performance in the presence of capacitor mismatches in the SC hardware implementation. In addition, by ensuring that the noise transfer function zeros are located at DC, the SC hardware implementation embodies a significant improvement in both capacitance spread and total capacitance
Keywords :
capacitance; circuit feedback; circuit noise; circuit stability; low-pass filters; sigma-delta modulation; signal sampling; switched capacitor networks; transfer functions; A/D converters; SC hardware implementation; capacitance spread; capacitor mismatches; complementary signal/noise transfer functions; instability; magnitude complementary noise transfer functions; magnitude complementary signal transfer functions; magnitude-squared noise transfer functions; magnitude-squared signal transfer functions; multiple-feedback Σ-Δ A/D converters; multiple-feedback lowpass Σ-Δ A/D converter; noise transfer function zeros; noise transfer functions; signal transfer functions; stability performance; stable multiple-feedback oversampled lowpass Σ-Δ A/D converter configuration; switched-capacitor hardware implementations; total capacitance; unit-circle noise transfer function zeros; Additive white noise; Capacitance; Capacitors; Frequency conversion; Hardware; Signal design; Signal to noise ratio; Stability; Switching converters; Transfer functions;
Conference_Titel :
Circuits and Systems, 2001. MWSCAS 2001. Proceedings of the 44th IEEE 2001 Midwest Symposium on
Conference_Location :
Dayton, OH
Print_ISBN :
0-7803-7150-X
DOI :
10.1109/MWSCAS.2001.986160
