A Wide Linearity, High Frequency, Wide Tunability Operational Transconductor Amplifier And Its Application For Filters

Since entering 21st century, the information industry of our country accelerate development greatly in production and scientific research, and has already become one of the pillars industry of national economic development. Microelectronic technique, electronic technology and computer technology with the close relations of mutually permeating, supporting and promoting each others, have gotten development at high speed . Meanwhile, with the progress of very large scale integration (VLSI) technology and urgent demand of the integrated trend of electronic system, the analog integrated circuit design method receives the extensive attention day by day. At present, The low voltage low power CMOS analog integrated circuit and the current mode circuit with a great deal of merits are concerned very much by theory researchers and project engineers for VLSI technology.The integrated filter is the important composition unit of the analog integrated circuit system and its circuit design method and synthesize technology have important reference and actual using value for studying the large scale integratedcircuit.This paper mainly researchs the prinples and the design methods of Operational- Transconductor-Amplifier(OTA) and OTA filters. At first the importance and present international and domestic research states of the analog integrated circuit are introduced , the model of MOS transistor and several kinds of basic integrated circuit unit module formed by MOS transistor are then introduced , for instance, basic current mirror and source coupled difference pairs and their principle and performance. Furthermore structure of the CMOS OTA is researched, and on the basis of summing up and analysing several kinds of classical OTA, a kind of improvement type OTA is proposed , which not only have wide linear input ranges, good frequency responds performance, but also have wide linear adjustment. At last, the design method of continuous time high frequency analog integrated OTA-C filter is introduced in detail, including passive LC ladder simulation, cascade and multiple feedback,etc. Pspice emulation results show the proposed OTA and OTA-C filters are feasible.