Linearly Tunable CMOS OTA With Constant Dynamic Range Using Source-Degenerated Current Mirrors

This brief introduces a new operational transconductance amplifier (OTA) that maintains the input voltage-swing constant during gm adjustments, enabled by employing current mirrors with source degeneration. The OTA presents a wide gm tuning range, which is linearly accomplished through a variable current source. The key design steps are illustrated through an example, and simulation results are included to validate the theory

[1]  Santiago Celma,et al.  A CMOS digitally tunable transconductor for video frequency operation [programmable filter applications] , 2003, Proceedings of the 2003 International Symposium on Circuits and Systems, 2003. ISCAS '03..

[2]  M. Tarsia,et al.  Design considerations and implementation of a programmable high-frequency continuous-time filter and variable-gain amplifier in submicrometer CMOS , 1999, IEEE J. Solid State Circuits.

[3]  H. A. Alzaher,et al.  A CMOS highly linear channel-select filter for 3G multistandard integrated wireless receivers , 2002 .

[4]  S. Dimitrijev.  Understanding semiconductor devices , 2000 .

[5]  Ramón González Carvajal,et al.  Compact tunable CMOS OTA with high linearity , 2004, 2004 IEEE International Symposium on Circuits and Systems (IEEE Cat. No.04CH37512).

[6]  Edgar Sanchez-Sinencio,et al.  A CMOS transconductance amplifier architecture with wide tuning range for very low frequency applications , 2002 .

[7]  R. Castello,et al.  An eighth-order CMOS lowpass filter with 30-120 Mhz tuning range and programmable boost , 2001, Proceedings of the 26th European Solid-State Circuits Conference.

[8]  A.A. Abidi,et al.  A broad-band tunable CMOS channel-select filter for a low-IF wireless receiver , 1999, IEEE Journal of Solid-State Circuits.

[9]  Andrea Baschirotto,et al.  0.18/spl mu/ CMOS Gm-C digitally tuned filter for telecom receivers , 2003, Proceedings of the 2003 International Symposium on Circuits and Systems, 2003. ISCAS '03..

[10]  Edgar Sanchez-Sinencio,et al.  A fully balanced pseudo-differential OTA with common-mode feedforward and inherent common-mode feedback detector , 2003, IEEE J. Solid State Circuits.

[11]  J. Mahattanakul,et al.  Current-mode versus voltage-mode G/sub m/-C biquad filters: what the theory says , 1998 .

[12]  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.

[13]  C. Dualibe,et al.  A linearly tunable low-voltage CMOS transconductor with improved common-mode stability and its application to g/sub m/-C filters , 2001 .

[14]  Marek Wojcikowski,et al.  A field programmable analog array for CMOS continuous-time OTA-C filter applications , 2002 .