A 1 V second order sigma-delta modulator

A second order switched capacitor sigma-delta modulator operating at a supply voltage of 1 V is presented. The design relies on the elimination of critical switches by using a modified switched op-amp for the integrator and novel switched half-supply and reference voltage generators. The design has been carried out in a fully differential configuration in order to minimize errors arising from charge injection and clock-feedthrough effects. The converter has been implemented using a conventional 0.8 /spl mu/m double-poly double-metal CMOS process and test results, showing more than 9 bits of resolution with oversampling ratio of 64, are presented.

[1]  Franco Maloberti,et al.  An high-swing, 1.8 V, push-pull opamp for sigma-delta modulators , 1998, 1998 IEEE International Conference on Electronics, Circuits and Systems. Surfing the Waves of Science and Technology (Cat. No.98EX196).

[2]  H. S. Fetterman,et al.  A 14-bit 80-kHz sigma-delta A/D converter: modeling, design and performance evaluation , 1989 .

[3]  Bruce A. Wooley,et al.  A 50-MHz multibit sigma-delta modulator for 12-b 2-MHz A/D conversion , 1991 .

[4]  W. Sansen,et al.  A 16-b 320-kHz CMOS A/D converter using two-stage third-order Sigma Delta noise shaping , 1993 .

[5]  J. Yamada,et al.  1 V power supply, low-power consumption A/D conversion technique with swing-suppression noise shaping , 1994 .

[6]  M. Steyaert,et al.  Switched-Opamp, a Technique for Realising full CMOS Switched-Capacitor Filters at Very Low Voltages , 1993, ESSCIRC '93: Nineteenth European Solid-State Circuits Conference.

[7]  Rudy Van De Plassche.  Integrated analog-to-digital and digital-to-analog converters / Rudy Van De Plassche , 1994 .

[8]  S. Au,et al.  A 1.95 V, 0.34 mW 12-bit sigma-delta modulator stabilized by local feedback loops , 1996, Proceedings of Custom Integrated Circuits Conference.

[9]  V. Peluso,et al.  A Switched Opamp 1.5V - 100μW ΔΣ Modulator with 12 bits Dynamic Range , 1996, ESSCIRC '96: Proceedings of the 22nd European Solid-State Circuits Conference.

[10]  William Martin Snelgrove,et al.  Switched-capacitor bandpass delta-sigma A/D modulation at 10.7 MHz , 1995, IEEE J. Solid State Circuits.

[11]  Bernhard E. Boser,et al.  The design of sigma-delta modulation analog-to-digital converters , 1988 .