Accurate multi-bit feedback DAC dedicated to high-speed Continuous-time ΔΣ converters

This paper presents the behavioral modeling and circuit design of an accurate multi-bit DAC dedicated to high-speed Continuous-time ΔΣ converters. The multi-bit DAC element mismatch is modeled, demonstrating that the non-linearities coming from the feedback DACs is awful for Continuous-time ΔΣ modulators. The proposed DAC is dimensioned in order to achieve best matching, reaching an unit current source relative standard deviation up to 0.7%. A full high-speed Continuous-time ΔΣ converter is implemented using the accurate DAC, achieving a SNR of 76 dB in a widebandwidth of 20 MHz.

[1]  C. S. Petrie,et al.  A multibit sigma-delta ADC for multimode receivers , 2003, IEEE J. Solid State Circuits.

[2]  P. Kiss,et al.  Digital techniques for improved /spl Delta//spl Sigma/ data conversion , 2002, Proceedings of the IEEE 2002 Custom Integrated Circuits Conference (Cat. No.02CH37285).

[3]  T. C. Leslie,et al.  An improved sigma-delta modulator architecture , 1990, IEEE International Symposium on Circuits and Systems.

[4]  M.J.M. Pelgrom,et al.  Matching properties of MOS transistors , 1989 .

[5]  Y. Deval,et al.  A software-defined radio based on sampled analog signal processing dedicated to digital modulations , 2007, 2007 Ph.D Research in Microelectronics and Electronics Conference.

[6]  K. Bult,et al.  A 10-b, 500-MSample/s CMOS DAC in 0.6 mm2 , 1998, IEEE J. Solid State Circuits.

[7]  Y. Deval,et al.  Continuous-Time Delta-Sigma Modulator based on High-Speed Low-Resolution A/D Converter , 2007, 2007 IEEE Northeast Workshop on Circuits and Systems.

[8]  Masao Nakaya,et al.  An 80-MHz 8-bit CMOS D/A converter , 1986 .

[9]  Michel Steyaert,et al.  A high yield 12-bit 250-MS/s CMOS D/A converter , 1996, Proceedings of Custom Integrated Circuits Conference.

[10]  Michel Steyaert,et al.  A 12-bit intrinsic accuracy high-speed CMOS DAC , 1998, IEEE J. Solid State Circuits.

[11]  Jan M. Rabaey,et al.  Digital Integrated Circuits: A Design Perspective , 1995 .

[12]  Hannu Tenhunen,et al.  A structure of cascading multi-bit modulators without dynamic element matching or digital correction , 2002, 2002 IEEE International Symposium on Circuits and Systems. Proceedings (Cat. No.02CH37353).

[13]  Marcel J. M. Pelgrom,et al.  Matching properties of MOS transistors , 1989 .