Abstract
This chapter deals with the design of DS modulators for wireless applications. Two case studies are presented to discuss general design issues and to give insights into the possibilities that exist for solving contemporary challenges with time-domain processing techniques. The first architecture employs a time-to-digital converter based on pulse-width. Its time-based single-level DAC achieves linear multi-bit feedback, leading to the DS modulator’s dynamic range of 68 dB. The second architecture employs a 7-phase 400 MHz clocking scheme to control time-based processing in the 3-bit two-step quantizer and DAC. Fabricated in a 0.18 μm CMOS technology, the 5th-order modulator achieves a peak SNDR of 67.7 dB in 25 MHz bandwidth, consumes 48 mW, and occupies a die area of 2.6 mm2. This modulator has a measured SFDR of 78 dB and in-band IM3 under −72 dB at −2dBFS.
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References
J.A. Cherry, W.M. Snelgrove, Continuous-Time Delta-Sigma Modulators for High-Speed A/D Conversion: Theory, Practice and Fundamental Performance Limits. (Kluwer, New York, 2002)
S.R. Norsworthy, R. Schreier, G.C. Temes, Delta-Sigma Data Converters: Theory, Design, and Simulation. (Wiley-IEEE Press, New York, 1996)
P. Malla, et al., A 28 mW spectrum-sensing reconfigurable 20 MHz 72dB-SNR 70dB-SNDR DT DS ADC for 802.11n/WiMAX receivers, in IEEE ISSCC Digest of Technical Papers, San Francisco, CA, Feb 2008, pp. 496–497
G. Mitteregger, et al., A 14 b 20 mW 640 MHz CMOS CT DS ADC with 20 MHz signal bandwidth and 12 b ENOB, in IEEE ISSCC Digest of Technical Papers, San Francisco, CA, Feb 2006, pp. 131–140
L.J. Breems, et al., A 56 mW CT quadrature cascaded SD modulator with 77 dB DR in a near zero-IF 20 MHz band, in IEEE ISSCC Digest of Technical Papers, San Francisco, CA, Feb 2007, pp. 238–239
G. Mitteregger, et al., A 20-mW 640-MHz CMOS continuous-time ΣΔ ADC with 20-MHz signal bandwidth, 80-dB dynamic range and 12-bit ENOB. IEEE J. Solid-State Circuits 41(12), 2641–2649 (2006)
M.Z. Straayer, M.H. Perrott, A 10-bit 20 MHz 38 mW 950 MHz CT ΣΔ ADC with a 5-bit noise-shaping VCO-based quantizer and DEM circuit in 0.13 u CMOS, in Proceedings of IEEE VLSI Circuits Symp., Kyoto, Japan, June 2007, pp. 246–247
M.Z. Straayer, M.H. Perrott, A 12-bit, 10-MHz bandwidth, continuous-time ΣΔ ADC with a 5-bit, 950-MS/s VCO-based quantizer. IEEE J. Solid-State Circuits. 43(4), 805–814 (2008)
R.E. Radke, A. Eshraghi, T.S. Fiez, A 14-bit current-mode ΣΔ DAC based upon rotated data weighted averaging. IEEE J. Solid-State Circuits. 35, 1074–1084 (2000)
E. Fogleman, I. Galton, A dynamic element matching technique for reduced-distortion multibit quantization in delta-sigma ADCs. IEEE Trans. Circ. Syst. II. 48(2), 158–170 (2001)
Y. Tsividis, Digital signal processing in continuous time: A possibility for avoiding aliasing and reducing quantization error, in Proceedings of International Conference on Acoustics, Speech, Signal Processing, Montreal, Canada, May 2004, vol. II, pp. 589–592
V. Dhanasekaran, M. Gambhir, M. Elsayed, E. Sanchez-Sinencio, J. Silva-Martinez, C. Mishra, L. Chen, and E. Pankratz, A 20 MHz BW 68 dB DR CT ΔΣ ADC based on a multi-bit time-domain quantizer and feedback element, in IEEE ISSCC Digest of Technical Papers, Feb 2009, pp. 174–175
V. Dhanasekaran, Baseband analog circuits in deep-submicron CMOS technologies targeted for mobile multimedia, Ph.D. Dissertation, Texas A&M University, College Station, TX, Aug 2008
H. Frank, U. Langmann, Excess loop delay effects in continuous-time quadrature bandpass sigma-delta modulators, in Proceedings of IEEE International Symposium on Circuits and Systems (ISCAS), vol. 1, May 2003, pp. 1029–1032
Y. Arai, T. Baba, A CMOS time to digital converter VLSI for high-energy physics, in IEEE VLSI Circuits Digest of Technical Papers, Tokyo, Japan, June 1988, pp. 121–122
S. Verma, et al., A unified model for injection-locked frequency dividers, IEEE J. Solid-State Circuits. 38(6), 1015–1027 (2003)
D.G. Holmes, T.A. Lipo, Pulse width modulation for power converters: Principles and practice. (IEEE Press, Piscataway, NJ, 2003)
C.-Y. Lu, M. Onabajo, V. Gadde, Y.-C. Lo, H.-P. Chen, V. Periasamy, J. Silva-Martinez, A 25 MHz bandwidth 5th-order continuous-time lowpass sigma-delta modulator with 67.7 dB SNDR using time-domain quantization and feedback. IEEE J. Solid-State Circuits. 45(9), 1795–1808 (2010)
F. Colodro, A. Torralba, New continuous-time multibit sigma-delta modulators with low sensitivity to clock jitter. IEEE Trans. Circ. Syst. I. 56(1), 74–83 (2009)
Y.-C. Lo, H.-P. Chen, J. Silva-Martinez, S. Hoyos, A 1.8 V, sub-mW, over 100% locking range, divide-by-3 and 7 complementary-injection-locked 4 GHz frequency divider, in Proceeding of IEEE Custom Integrated Circuits Conference (CICC), Sept 2009, pp. 259–262
B.K. Thandri, J. Silva-Martinez, A robust feedforward compensation scheme for multi-stage operational transconductance amplifiers with no miller capacitors. IEEE J. Solid-State Circuits 38, 237–243 (2003)
C.-Y. Lu, F. Silva-Rivas, P. Kode, J. Silva-Martinez, S. Hoyos, A 6th-order 200 MHz IF bandpass sigma-delta modulator with over 68 dB SNDR in 10 MHz bandwidth. IEEE J. Solid-State Circuits. (to be published (2010))
F. Silva-Rivas, C.-Y. Lu, P. Kode, B.K. Thandri, J. Silva-Martinez, Digital based calibration technique for continuous-time bandpass sigma-delta analog-to-digital converters. Analog Integr. Circ. S. 59, 91–95 (2009)
B. Verbruggen, et al., A 2.2 mW 1.75 GS/s 5 bit folding flash ADC in 90 nm digital CMOS. IEEE J. Solid-State Circuits. 44(3), 874–882 (2009)
W. Yang, et al., A 100 mW 10 MHz-BW CT ΔΣ modulator with 87 dB DR and 91dBc IMD, in IEEE ISSCC Digest of Technical Papers, Feb 2008, pp. 498–631
Acknowledgements
The authors would like to recognize that these ADCs were developed with the collaboration of Prof. E. Sanchez-Sinencio, M. Elsayed, E. Pankratz, Y. C. Lo, V. Gadde, and V. Periasamy. The authors appreciate the chip fabrications sponsored by Texas Instruments and Jazz Semiconductor.
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Silva-Martinez, J., Lu, CY., Onabajo, M., Silva-Rivas, F., Dhanasekaran, V., Gambhir, M. (2011). Wideband Continuous-Time Multi-Bit Delta-Sigma ADCs. In: Casier, H., Steyaert, M., van Roermund, A. (eds) Analog Circuit Design. Springer, Dordrecht. https://doi.org/10.1007/978-94-007-0391-9_11
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DOI: https://doi.org/10.1007/978-94-007-0391-9_11
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