Wide-linear-range subthreshold OTA for low-power, low-Voltage, and low-frequency applications

• Published in: IEEE transactions on circuits and systems. I, Regular papers Vol. 52; no. 8; pp. 1481 - 1488
• Main Authors: Mourabit, A.E., Guo-Neng Lu, Pittet, P.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-08-2005; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Circuit testing; CMOS process; Diodes; Electronics; Engineering Sciences; Linearization; Linearization techniques; low; low power; low supply; Low voltage; Micro and nanotechnologies; Microelectronics; MOS devices; MOSFETs; multiple input floating-gate (MIFG) MOS transistor; Operational amplifiers; Optics; Parasitic capacitance; Photonic; Signal and Image processing; subthreshold operational transconductance amplifier (OTA); Transconductance
• ISSN: 1549-8328; 1558-0806
• DOI: 10.1109/TCSI.2005.852011

We propose a novel configuration of linearized subthreshold operational transconductance amplifier (OTA) for low-power, low-voltage, and low-frequency applications. By using multiple input floating-gate (MIFG) MOS devices and implementing a cubic-distortion-term-canceling technique, the linear range of the OTA is up to 1.1 Vpp under a 1.5-V supply for less than 1% of transconductance variation, according to testing results from a circuit designed in a double-poly, 0.8-/spl mu/m, CMOS process. The power consumption of the OTA remains below 1 /spl mu/W for biasing currents in the range between 1-200 nA. The offset voltage due to secondary effects (contributed by parasitic capacitances, errors and mismatches of parameters, charge entrapment, etc.) is of the order of a few ten millivolts, and can be canceled by adjusting biasing voltages of input MIFG MOS transistors.