New ELIN Systems Using CMOS Transistors in Weak Inversion Operation

In this paper new ELIN systems implemented by using CMOS transistors in weak inversion operation are presented. The proposed systems exploit the exponential-law characteristics of the subthreshold CMOS transistors. New operational transconductance amplifiers in CMOS technology, providing elementary tanh and sinh/cosh functions with high accuracy are proposed. These elementary cells are used to design first order CMOS ELIN filters. For a bias current of 1�A, the dynamic range of the predistorted input voltage is 220mVpp and the current consumption is about 20uA from a 3.3V supply voltage. The simulations performed in 0.18um CMOS technology confirm the theoretically obtained results

A New Linearization Technique Using Multi-sinh Doublet

In this paper a new linearization technique using multi-sinh doublet, implemented with a second generation current conveyor is presented. This new linearization technique is compared with the one based on multi-tanh doublets with linearization series connected diodes on the branches. The comparative study of the two linearization techniques is carried out using both dynamic range analysis, expressed by linearity error and the THD value calculation of output current, and the noise behavior of the two analyzed doublets. For the multi-sinh linearization technique proposed in the paper a method which assures the increase of the dynamic range, keeping the transconductance value constant is presented. This is done by using two design parameters: the number of series connected diodes N, which specifies the desired linear operating range and the k emitters areas ratio of the input stage transistors, which establishes the transconductance value. In the paper is also shown that if the transconductances of the two analyzed doublets are identical, and for the same values of N and k parameters, respectively, the current consumption of the multi-sinh doublet is always smaller than for the multi-tanh doublet