1-V Low-Power Programmable Rail-to-Rail Operational Amplifier With Improved Transconductance Feedback Technique

• Published in: IEEE transactions on very large scale integration (VLSI) systems Vol. 21; no. 10; pp. 1928 - 1935
• Main Authors: Shanshan Dai, Xiaofei Cao, Ting Yi, Hubbard, Allyn E., Zhiliang Hong
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.10.2013; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amplifiers; Applied sciences; Circuit properties; CMOS; Constant transconductance; Design. Technologies. Operation analysis. Testing; Deviation; Electric, optical and optoelectronic circuits; Electrical engineering. Electrical power engineering; Electronic circuits; Electronic equipment and fabrication. Passive components, printed wiring boards, connectics; Electronics; Exact sciences and technology; Feedback loop; Fluctuation; Integrated circuits; Logic gates; low power; operational amplifier; Operational amplifiers; Power electronics, power supplies; programmable; rail-to-rail; Rails; Resistance; Resistors; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Transconductance; Transistors; Very large scale integration; Operational amplifier; programmable; Feedback regulation; Power supply; Rail to rail characteristics; Power electronics; rail-to-rail; Feedback; Complementary MOS technology; Constant transconductance; low power; Low-power electronics; Resistor; Figure of merit; Gain; Transconductance
• ISSN: 1063-8210; 1557-9999
• DOI: 10.1109/TVLSI.2012.2220387

A low-power process-independent programmable transconductance rail-to-rail operational amplifier (OpAmp) is proposed. It employs an improved transconductance feedback loop that senses the transconductance (g mT ) accurately and enforces it to be equal to the conductance of a reference resistor. Experimental results in a 0.13- μm standard CMOS technology under a 1-V power supply demonstrate a continuous programmable g mT range from 87 to 165 μA/V with minimum fluctuation of ±2.4% and programmable deviation less than 4.5% from the reference value. The OpAmp achieves a unity-gain bandwidth of 3.7 MHz with a 95-pF load while only consuming 187 μA of quiescent current. The figure of merit of the proposed OpAmp is 1879 MHz·pF/mA.