Title :
A novel double sampling technique for delta-sigma modulators
Author :
Yang, Hong-Kui ; El-Masry, Ezz I.
Author_Institution :
Dept. of Electr. Eng., Tech. Univ. Nova Scotia, Halifax, NS, Canada
Abstract :
The double sampling technique is used to achieve twice the sampling frequency in sampled-data systems without extra requirements (e.g., clock rate, op-amp settling time, op-amp dc gain, etc.). In this paper, theoretical analyses of the effects of nonidealities (integrator leakage, path gain mismatch and non-uniform sampling) on the performance of double sampling delta-sigma modulators (ΔΣM´s) are given. A novel double sampling technique for ΔΣM´s which is insensitive to the path gain mismatch is also presented. This technique uses a bilinear integrator in the first stage, resulting in a first order shaping of the path gain mismatch error. Compared with a second-order single sampling ΔΣM, this technique is able to achieve 15 dB improvement of S/N and 6 dB relaxation of op-amp dc gain
Keywords :
sampled data circuits; sigma-delta modulation; signal sampling; bilinear integrator; delta-sigma modulators; double sampling; integrator leakage; nonidealities; nonuniform sampling; op-amp DC gain relaxation; path gain mismatch error; sampled-data systems; signal noise ratio; Bandwidth; Capacitors; Clocks; Data systems; Delta modulation; Frequency; Operational amplifiers; Performance analysis; Performance gain; Sampling methods; Signal to noise ratio; Silicon compounds;
Conference_Titel :
Circuits and Systems, 1994., Proceedings of the 37th Midwest Symposium on
Conference_Location :
Lafayette, LA
Print_ISBN :
0-7803-2428-5
DOI :
10.1109/MWSCAS.1994.519021