EOTA-Based Field Programmable Analog Array Design And Application

With the rapid development of electronic circuits, especially is the appearance ofFPGA, CPLD and other programmable devices, the designing of digital circuit isbecoming more and more convenient, and causing a new development tide in thedigital circuit region. Compared to the rapid development of digital circuit, analogcircuit seems to discourage. Inspired by FPGA, analog circuit designers haveproposed a new type of analog circuit with low price, called as Field ProgrammableAnalog Array (FPAA), which can set up its circuit functions according to the fieldneed and can be programmed at any time to modify its parameters. Due to thesefunctions, FPAA can be widely used in the fields of signal processing, automaticcontrol, wireless transceiver, artificial neural network. Now numerous of foreignenterprises and research institutions have invested a great deal of effort on FPAA fordepth research, while our country is still in its infancy.In this paper, a large number of work was put into the study of the linearlytunable OTA-based FPAA circuit. The major completed work are as follow:(1) To overcome the shortcoming that OTA’ s transconductance can not be tunedlinearly and the tunable range is narrow, a new linearly tunable OTA was proposed,which is using a class AB current mirror and two basic OTAs.(2) Designed an analog programmable basic cell (CAB), which is composed by alinearly tunable OTA, a capacitance multiplier, a programmable current minor arrayand a programmable switching network. Connected these CABs by using thehexagonal interconnection network, a novel FPAA circuit based on the linear tunableOTA and current-mode continuous-time technology was formed. The obtained FPAAcircuit achieves many advantages, such as simple structure, easy to program, widebandwidth, low power consumption, etc.(3) Proposed an OTA-based reconfigurable current-mode filter model by usingthe integrated design analysis method, and employed the FPAA circuit to achieve it.The proposed filter circuit can achieve any type, any form and any order (N≥2)filtering, and its filtering parameters can be tuned easily. PSPICE software was usedto verify the performances.(4) Proposed a new method to achieve the mutually coupled circuit bysimplifying its mathematical model, and employed the FPAA circuit to achieve the concrete circuit. The proposed mutually coupled circuit obtained many advantages,such as simple structure, self-inductance and mutual inductance can be tunedindependently, without passive resistors and lossy integrator, low power consumption.Therefore，it solved the problem of the mutual inductance coupling circuit is not easyto integrate. Then the proposed circuit was used in the current-mode double-tunedcircuit, and the simulation results verified its usefulness.(5) Used the FPAA circuit to achieve some analog signal processing circuits,such as tunable gain amplifier, analog gyrator, voltage adder, etc. PSPICE simulationresults verify the performance of these circuits.