Title :
Automatic Tuning of Time Constants in Continuous-Time Delta–Sigma Modulators
Author :
Pavan, Shanthi ; Krishnapura, Nagendra
Author_Institution :
Dept. of Electr. Eng., Indian Inst. of Technol. Madras, Chennai
fDate :
4/1/2007 12:00:00 AM
Abstract :
We describe a digital technique for estimating and correcting time constant shifts in continuous-time delta-sigma modulators. The proposed method is based on the principle that the in-band gain and the out-of-band performance of a modulator are related. If the modulator output is denoted as v(n), we show that the variance of p(n)equivv(n)-v(n-1) is a good indicator of the modulator RC time constants. An alternative indicator, which is easier to implement in hardware is proposed. Simulation results demonstrating the effectiveness of the proposed techniques are given
Keywords :
circuit tuning; delta-sigma modulation; RC time constants; constant shifts; continuous-time SigmaDelta modulators; continuous-time delta-sigma modulators; digital technique; in-band gain; noise transfer function; out-of-band performance; time constant automatic tuning; time correcting; time estimating; Capacitors; Circuit noise; Delta modulation; Digital modulation; Filters; Frequency; Oscillators; Quantization; Transfer functions; Tuning; Continuous-time $SigmaDelta$ modulators (CT-DSM); noise transfer function (NTF);
Journal_Title :
Circuits and Systems II: Express Briefs, IEEE Transactions on
DOI :
10.1109/TCSII.2006.888920