This paper presents design methodology and comparison of a 1-bit DAC in both 180 nm and 90 nm CMOS technologies. A 1-bit digital-to-analog converter (DAC) is designed and simulated in 180 nm and 90 nm CMOS technologies using Cadence Virtuoso tool. This DAC can be used in the feedback path of Delta-Sigma modulators. Delta-Sigma ADC is the most robust type of ADC which is highly immune to noise compare to that of ordinary analog-to-digital converters.

1. K. Dobson, S. Ahmadi, and M. Zaghloul, "A 1. 2 ghz band-pass sigma delta analog to digital modulator with active inductor based resonators," in Proceedings of the World Congress on Engineering and Computer Science, vol. 2, 2012.
2. R. Schreier and G. C. Temes, Understanding delta-sigma data converters, vol. 74. IEEE press Piscataway, NJ, 2005.
3. B. P. Brandt, D. E. Wingard, and B. A. Wooley, "Second-order sigma-delta modulation for digital-audio signal acquisition," Solid-State Circuits, IEEE Journal of, vol. 26, no. 4, pp. 618– 627, 1991.
4. J. A. Cherry and W. M. Snelgrove, Continuous-time delta-sigma modulators for high-speed A/D conversion: theory, practice and fundamental performance limits, vol. 521. Springer Science & Business Media, 2000.
5. A. Tabatabaei and B. A. Wooley, "A wideband band pass sigma-delta modulator for wireless applications," in VLSI Circuits, 1999. Digest of Technical Papers. 1999 Symposium on, pp. 91– 92, IEEE, 1999.
6. I. Galton, "Noise-shaping d/a converters for ds modulation," in Circuits and Systems, 1996. ISCAS'96. , Connecting the World. , 1996 IEEE International Symposium on, vol. 1, pp. 441–444, IEEE, 1996.
7. Y. Li and L. He, "First-order continuous-time sigma-delta mod-ulator. ," in ISQED, pp. 229–232, 2007.
8. J. A. Cherry and W. M. Snelgrove, "Clock jitter and quantizer metastability in continuous-time delta-sigma modulators," Cir-cuits and Systems II: Analog and Digital Signal Processing, IEEE Transactions on, vol. 46, no. 6, pp. 661–676, 1999.
9. R. J. Van de Plassche, "Cmos integrated analog-to-digital and digital-to-analog converters," vol. 2, Kluwer Academic Publish-ers Dordrecht, 2003.
10. M. Kosakowski, R. Wittmann, and W. Schardein, "Statistical averaging based linearity optimization for resistor string dac architectures in nanoscale processes," in SOC Conference, 2008 IEEE International, pp. 261–266, IEEE, 2008.
11. D. A. Johns and K. Martin, "Analog integrated circuit design," John Wiley & Sons, 2008.
12. R. L. Geiger, P. E. Allen, and N. R. Strader, "Vlsi design techniques for analog and digital circuits," vol. 90, McGraw-Hill New York, 1990.

Dac Delta-sigma Modulator 90 Nm 180 Nm