Two digitally programmable gain amplifiers based on current conveyors

Two digitally programmable gain amplifiers based on current conveyors (CCIIs) are presented. The first digitally programmable gain amplifier consists of a CCII, an operational transconductance amplifier (OTA), and current mirrors. The second one is composed of current conveyor analogue switches (CCASs). Both proposed digitally programmable gain amplifiers do not need switches but they maintain the linear gain at any digital signal levels similar to the digitally programmable gain amplifier using switches; hence the proposed amplifiers are easier to realize, use narrower chip area, and consume lower power. The first proposed amplifier is verified by constructing the circuit using the CCII in an AD844 IC, the OTA in a CA3080 IC, and some bipolar current mirrors. The second proposed amplifier is verified by simulating the circuit using the parameters extracted from the layout (including parasitic capacitance) in the 0.25 μm MOS technology, the level 49 MOS model obtained through MOSIS is used. The results show that the operations of two proposed amplifiers are in accordance with the theories.

[1]  José Silva-Martínez,et al.  A High Dynamic Range CMOS Variable Gain Amplifier for Mobile DTV Tuner , 2007, IEEE Journal of Solid-State Circuits.

[2]  B.B. Woo.  Digitally programmable gain amplifiers with arbitary range of integer values , 1980, Proceedings of the IEEE.

[3]  B. Calvo,et al.  High-frequency digitally programmable gain amplifier , 2003 .

[4]  Suhash C. Dutta Roy,et al.  Digitally Programmable Gain Amplifiers , 1984, IEEE Transactions on Instrumentation and Measurement.

[5]  Bonkee Kim,et al.  A 13-dB IIP3 improved low-power CMOS RF programmable gain amplifier using differential circuit transconductance linearization for various terrestrial mobile D-TV applications , 2006 .

[6]  Santiago Celma,et al.  Using MOS current dividers for linearization of programmable gain amplifiers , 2008 .

[7]  Jean-Pierre Chante,et al.  A current conveyor-based high-frequency analog switch , 1998 .

[8]  Adisak Monpapassorn.  An analogue switch using a current conveyor , 2002 .

[9]  Z. Wang,et al.  2-MOSFET transresistor with extremely low distortion for output reaching supply voltages , 1990 .

[10]  J.J.F. Rijns.  CMOS Low-Distortion High-Frequency Variable-Gain Amplifier , 1995, ESSCIRC '95: Twenty-first European Solid-State Circuits Conference.

[11]  Kobchai Dejhan,et al.  CMOS-based near zero-offset multiple inputs max–min circuits and its applications , 2009 .

[12]  Erik Bruun.  CMOS high speed, high precision current conveyor and current feedback amplifier structures , 1993 .

[13]  Jieh-Tsorng Wu,et al.  A highly linear 125-MHz CMOS switched-resistor programmable-gain amplifier , 2003, IEEE J. Solid State Circuits.

[14]  Hassan Elwan,et al.  Digitally programmable decibel-linear CMOS VGA for low-power mixed-signal applications , 2000 .

[15]  Steve Moore.  Designing with Analog Switches , 1991 .

[16]  L. C. Jain,et al.  Economical and accurate digitally programmable dual-polarity gain amplifier , 1995 .

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

[18]  Tejmal S. Rathore.  Digitally controlled amplifiers with fewer resistors and sensitivities , 1983 .