Title :
Harmonic distortion in SC sigma-delta modulators
Author :
Dias, V.F. ; Palmisano, G. ; Maloberti, F.
Author_Institution :
INESC, Lisbon, Portugal
fDate :
4/1/1994 12:00:00 AM
Abstract :
The maximum achievable resolution in noise-shaping modulators is a function of three principal parameters: oversampling ratio, M; noise-shaping order, L; and quantizer resolution, N. For practical implementations, thermal noise in MOS switches and amplifiers, bandwidth and slew-rate in integrator circuits in switched-capacitor (SC) implementations, and jitter noise in continuous-time (CT) and mixed CT-SC realizations have to be considered. This paper deals with harmonic distortion, which is a third design constraint in high-resolution SC noise-shaping modulators. Here we analyze harmonic distortion due to the nonideal DC-gain characteristic of operational amplifiers and derive a relationship for a standard SC integrator. Simulation results from a behavioral simulator we have developed validate the analysis
Keywords :
analogue-digital conversion; delta modulation; electric distortion; harmonics; integrating circuits; modulators; switched capacitor networks; thermal noise; ADC; MOS amplifiers; MOS switches; SC sigma-delta modulators; bandwidth; behavioral simulator; continuous-time; harmonic distortion; high-resolution; integrator circuits; jitter noise; mixed CT-SC realizations; noise-shaping modulators; noise-shaping order; nonideal DC-gain characteristic; operational amplifiers; oversampling ratio; quantizer resolution; slew-rate; switched-capacitor; thermal noise; Analytical models; Bandwidth; Circuit noise; Delta-sigma modulation; Harmonic distortion; Jitter; Noise shaping; Signal to noise ratio; Switches; Switching circuits;
Journal_Title :
Circuits and Systems I: Fundamental Theory and Applications, IEEE Transactions on
