Binary Genetic Encoding for the Synthesis of Mixed-Mode Circuit Topologies

Abstract

A binary genetic encoding (BGE) representation for the automatic synthesis of mixed-mode circuit topologies, is introduced. First, the genetic encoding of unity-gain cells (UGCs), such as voltage (VF) and current followers (CF), and voltage (VM) and current mirrors (CM), is presented. New BGEs for the VM and CM are introduced. Second, the UGC's chromosomes are combined to synthesize mixed-mode circuit-topologies, namely current conveyors and current-feedback operational amplifiers (CFOA). Five strategies for the combination or superimposing of UGCs are introduced. The proposed BGE has been implemented in MATLAB TM , and links SPICE to evaluate the populations with different integrated circuit technologies. Some new synthesized circuit topologies are shown along with their chromosome description.

Integrated circuit generating 3- and 5-scroll attractors

“…It can be designed by using different active devices like the ones given in [12]. In this work we use unity-gain cells (UGCs) due to their relatively compact implementation.…”

“…The integration operation is carried out by the current flowing trough external capacitors C, with gain 1 R , thus the dominant time-constant of the dynamical system is RC, with s ¼ t RC . The IC implementation should take into account several design aspects, for example: wide swing, because an increase on the number of scrolls for the same dynamic range of the active devices [12], will eventually cause the loss of the chaotic behavior due to the noise and circuit fault tolerances; high bandwidth, because the frequency limit of the active devices is directly affecting the PWL function [13], i.e. the transistors are changing their operation mode; high modularity, because the nonlinear function should grow in a systematic mode, according to the desired number of scrolls to be generated, i.e.…”

CDCTA and OTA Realizations of a Multi-phase Sinusoidal Oscillator

“…In our proposed OTA realization of the MSO, we do not use current-differencing units [15]. We use only two three-output OTAs that can be generated by augmenting the current outputs using CMs, which can be designed as already shown in [18]. In this manner, our proposed first-order all-pass section does not require the DO-CM needed in Figure 5.…”

Frequency limitations in generating multi-scroll chaotic attractors using CFOAs

“…The CFOA is a mixed-mode active device (Duarte-Villaseñor et al, 2012), quite useful to implement filters (Gupta, Bhaskar, & Senani, 2011), and oscillators (Elwakil & Kennedy, 2000;Gopakumar, Premlet, & Gopchandran, 2011;Gopakumar et al, 2011;Kilic, 2003;Sánchez-López, 2012;Soliman, 2011;Tlelo-Cuautle, Gaona-Hernández, & GarciaDelgado, 2006;Trejo-Guerra, Tlelo-Cuautle, Sánchez-López, Muñoz-Pacheco, & CruzHernández, 2010;), and it is commercially available as CFOA AD844. Besides, its frequency limitation characteristics , has not been yet presented experimentally.…”

“…That chaotic oscillator can produce multi-scroll attractors in one (1D), two (2D) and three directions (3D), while the SNLFs can be modeleed by piecewise-linear (PWL) functions. From the circuit design point of view, chaotic oscillators have been implemented using different kinds of active devices (Duarte-Villaseñor, Tlelo-Cuautle, & de la Fraga, 2012;Muñoz-Pacheco, Campos-López, Tlelo-Cuautle, & Sánchez-López, 2012), and those designs have been used to implement secure communication systems by CarbajalGómez, Tlelo-Cuautle, Trejo-Guerra, . In the majority of cases, operational amplifiers (opamps) have been the warhorses to implement multi-scroll chaotic oscillators (Lü & Chen, 2006).…”