论文信息 - A tunable triode-MOSFET transconductor and its application to g/sub m/-C filters

A tunable triode-MOSFET transconductor and its application to g/sub m/-C filters

A linear, tunable CMOS transconductance stage is introduced. Drain voltage of the input transistor operating in triode region is settled by a regulation loop and a first-order linear relationship between g/sub m/ and a DC bias voltage is achieved. In addition to easy tuning, this technique offers circuit simplicity, wide dynamic range, high input and output impedances and low consumption. The transconductor is presented on both single-ended and fully-differential versions. A 3rd-order elliptical low-pass g/sub m/-C filter with a nominal roll-off frequency of 2 MHz is used as one example for the many applications of the proposed transconductor. SPICE data describe circuits performances and filter tunability. Passband is tuned at a rate of 2.36 KHz/mV and good linearity is indicated by a 0.89% THD for an 800 mV/sub p-p/ balanced-driven input.

Jader A. De Lima | Carlos Dualibe

[1] A. Kaiser. A Micropower CMOS Continuous-Time Lowpass Filter , 1988, ESSCIRC '88: Fourteenth European Solid-State Circuits Conference.

[2] Wouter A. Serdijn. Low-Voltage Low-Power Analog Integrated Circuits , 1995 .

[3] Chul Soon Park,et al. A high-frequency CMOS linear transconductance element , 1986 .

[4] Yannis Tsividis,et al. Continuous-time MOSFET-C filters in VLSI , 1986 .

[5] David A. Johns,et al. Analog Integrated Circuit Design , 1996 .

[6] T. Kwan,et al. An adaptive analog continuous-time CMOS biquadratic filter , 1991, Proceedings of the IEEE 1991 Custom Integrated Circuits Conference.

[7] W. Guggenbuhl,et al. A high-swing, high-impedance MOS cascode circuit , 1990 .

[8] G. Geelen,et al. A fast-settling CMOS op amp for SC circuits with 90-dB DC gain , 1990 .

[9] Jaime E. Kardontchik,et al. Introduction to the design of transconductor-capacitor filters , 1992, The Kluwer international series in engineering and computer science.

[10] Rolf Schaumann,et al. Continuous-Time Filters , 1993 .

[11] Francois Krummenacher,et al. A 4-MHz CMOS Continuous-Time Filter with On-Chip Automatic Tuning , 1987, ESSCIRC '87: 13th European Solid-State Circuits Conference.

[12] Y. Tsividis. Operation and modeling of the MOS transistor , 1987 .

[13] P. R. Gray,et al. High-frequency CMOS continuous-time filters , 1984 .

[14] J. L. Pennock. CMOS triode transconductor for continuous-time active integrated filters , 1985 .