Title :
On the effect of comparator hysteresis in interpolative ΔΣ modulators
Author :
Khoini-Poorfard, R. ; Johns, D.A.
Author_Institution :
Dept. of Electr. Eng., Univ. of Toronto, Ont., Canada
Abstract :
Comparator hysteresis of a 1-bit quantizer in Δ-Σ interpolative modulators is considered. A theoretical framework based on the describing function method is derived which enables estimation of the maximum and the minimum level at the input of the comparator, as well as the period of limit cycles with respect to the input. The results are in good agreement with simulation results, showing that hysteresis has a twofold worsening effect, i.e., increasing noise power and shifting the noise spectrum toward the signal band
Keywords :
comparators (circuits); integrated circuit noise; interpolation; limit cycles; quantisation (signal); sigma-delta modulation; comparator hysteresis; describing function method; interpolative ΔΣ modulators; limit cycles; noise power; noise spectrum; quantizer; signal band; twofold worsening effect; Amplitude modulation; Delta modulation; Doped fiber amplifiers; Frequency; Hysteresis; Nonlinear equations; Power harmonic filters; Predictive models; Sampling methods; Transfer functions;
Conference_Titel :
Circuits and Systems, 1993., ISCAS '93, 1993 IEEE International Symposium on
Conference_Location :
Chicago, IL
Print_ISBN :
0-7803-1281-3
DOI :
10.1109/ISCAS.1993.393908
