IMPLEMENTATION OF VARIOUS FILTERS USING OTRA

Abstract

The low-voltage and low-power mixed mode circuit design has gained importance with the advent of the portable electronic and mobile communication systems. More and more mixed mode circuit blocks, are being integrated onto a single chip in an effort to reduce overall cost and space and to improve system performance. This requires the scaling of CMOS technology. The reliability and density factors associated with technology scaling demand for downsized supply voltages. This trend of continuous reduction of the supply voltage poses serious challenges to the analog designers. To circumvent this conflict instead of using costly CMOS technologies with lower thresholds, it is desirable to use low voltage circuit techniques that are compatible with standard CMOS processes. In the last few decades the current-mode processing has emerged as an alternative design technique. Ever shrinking feature size of devices on ICs and consequential reduction of power supply voltage can be handled by operating in the current domain, as current mode circuits are designed for lower voltage swings. While fundamentally any design techniques is limited by device characteristics, there may be specific applications where current-mode circuits provide one or more of the following advantages: higher bandwidth, better signal linearity, higher slew rates, lower power consumption, and better accuracy. Additionally, current-mode circuits are often less complex than the voltage-mode circuits, which may lead to significant chip area savings. Emergence of various current-mode analog building blocks is outcome of the considerable progress in current-mode analog signal processing. Operational trans-resistance amplifier (OTRA) among those is of relatively recent origin.