Coded data generation or conversion – Analog to or from digital conversion – Differential encoder and/or decoder
Patent
1996-01-17
1998-03-17
Fleming, Fritz
Coded data generation or conversion
Analog to or from digital conversion
Differential encoder and/or decoder
341155, 341118, H03M 300
Patent
active
057292302
ABSTRACT:
A continuous-time tunable Gm-C architecture for a .DELTA..SIGMA. modulator includes a tunable resonator and a low bit rate, high sample rate quantizer connected in a feedback loop. The resonator shapes the quantization noise spectrum so that the bulk of the quantization noise occurs outside the signal spectrum. A tunable Gm cell tunes the resonator's resonant frequency to maximize the modulator's SNR. The tunable Gm cell includes a fixed Gm cell having transconductance G.sub.f, a current divider and a recombination circuit that together effectively multiply G.sub.f by a factor .alpha., where -1<=.alpha.<=1, without effecting the cell's common mode current I.sub.cm. A positive current source supplies I.sub.cm, while maintaining a common mode resistance of R/2 and a theoretically infinite differential mode resistance. Thus, the resonator's resonant frequency can be varied from DC to approximately 1 Ghz while maintaining a stable common mode operating point and improving the modulator's quality factor.
REFERENCES:
patent: 4774518 (1988-09-01), Fukuhara
patent: 4799025 (1989-01-01), La Quean
patent: 4857928 (1989-08-01), Gailus et al.
patent: 5055843 (1991-10-01), Ferguson, Jr. et al.
patent: 5157350 (1992-10-01), Rubens
patent: 5182477 (1993-01-01), Yamasaki
patent: 5371475 (1994-12-01), Brown
patent: 5392042 (1995-02-01), Pellon
patent: 5491477 (1996-02-01), Goetschel et al.
patent: 5500645 (1996-03-01), Ribner et al.
"Sigma-Delta ADCs and DACs, Sigma-Delta Overview", Mixed Signal Design Seminar, Analog Devices, Inc. Section VI:1-12, 1991.
Comino et al., "A First-Order Current-Steering Sigma-Delta Modulator", IEEE Journal of Solid-State Circuits, vol. 26, No. 3, Mar. 1991, pp. 176-183.
Shoaei et al., "Optimal (Bandpass) Continuous-Time .SIGMA..DELTA. Modulator", Proceedings ISCAS, vol. 5, pp. 489-492, 1994.
Heij et al., "Transconductor and Integrator Circuits for Integrated Bipolar Video Frequency Filters", Proceeding of ISCAS, 1989, pp. 114-117.
Voorman et al., "Integration of Analog Filters in a Bipolar Process", IEEE Journal of Solid State Circuits, vol. SC-17, No. 4, Aug. 1982, pp. 713-722.
Veirman et al., "Design of a Bipolar 10-MHz Programmable Continuous-Time 0.05.degree. Equiripple Linear Phase Filter", IEEE Journal of Solid-State Circuits, vol. 27, No. 3, Mar. 1992, pp. 324-331.
Sansen et al., "Distortion in Bipolar Transistor Variable-Gain Amplifiers", IEEE Journal of Solid-State Circuits, vol. SC-8, No. 4, Aug. 1973, pp. 275-282.
Singor et al., "Switched-Capacitor Bandpass Delta-Sigma A/D Modulation at 10.7 MHz", IEEE Journal of Solid-State Circuits, vol. 30, No. 3, Mar. 1995, pp. 184-192.
Yang, S., et al. "A Tunable Bandpass Sigma-Delta A/D Conversion for Mobile Communication Receiver" Dept. of Electrical and Electronic Engineering, Victoria University of Technology, 1994 IEEE, pp. 1346-1350.
Shoaei, O., et al. "Optimal (Bandpass) Continuous-Time .DELTA..SIGMA. Modulator" Dept. of Electronics, Carleton University, Ottawa, Ontario, Canada K1S 5B6, (1994) pp. 489-492.
de Heij, W.J.A., et al. "Transconductor and Integrator Circuits For Integrated Bipolar Video Frequency Filters" University of Twenty, The Netherlands, pp. 114-117.
Cosand Albert E.
Jensen Joseph F.
Raghavan Gopal
Denson-Low W. K.
Duraiswamy V. D.
Fleming Fritz
Hughes Aircraft Company
Kost Jason L. W.
LandOfFree
Delta-Sigma .DELTA.-.SIGMA. modulator having a dynamically tunab does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Delta-Sigma .DELTA.-.SIGMA. modulator having a dynamically tunab, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Delta-Sigma .DELTA.-.SIGMA. modulator having a dynamically tunab will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-961848