Novel low-voltage low-power high-precision CCII ± based on bulk-driven folded cascode OTA

This paper presents possible approaches to the design of a novel low-voltage, low-power, and high-precision current conveyor of the second generation (CCII) based on the bulk-driven folded cascode operational transconductance amplifier (OTA) with extended input common-mode voltage range. This CCII +/- utilizes bulk-driven differential pairs to obtain a nearly rail-to-rail input stage at a low supply voltage. The proposed conveyor operates at a low supply voltage of +/- 400 mV with a reduced power consumption of only 64 mu W. A current-mode multifunction filter is presented as an application of the CCII. This filter provides five transfer functions simultaneously, namely low-pass, band-pass, high-pass, notch, and all-pass. The filter has the following properties and advantages: it employs three bulk-driven current conveyors BD-CCII, three grounded resistors, and two grounded capacitors, which is suitable for integrated circuit implementation. Furthermore, the input signal is connected to the low-impedance X terminal of the BD-CCII +/- whereas the output signals are taken from the high-impedance output terminals Z+ and Z-. Finally, the pole frequency and quality factor of the designed filter are tunable independent of each other. PSpice simulation results using the 0.18 mu m CMOS technology are included to prove the results. (C) 2011 Elsevier Ltd. All rights reserved.