MOSFETS Power Consumption and Power Dissipation Calculation

Abstract

Metal oxide semiconductor field effect transistors are usually called MOSFET. Nowadays, MOSFET is one of the most crucial electrical components that engineers usually use when constructing laptops and desktop computers. A large number of MOSFETS are usually integrated together to form control and logic functions of computers CPU. Thus, it is essential for electrical engineers to know what type of MOSFETS is appropriate for them to use when designing the integrated circuits. Engineers can seek the answer through calculating two of the most basic and important components of MOSFET power consumption and power dissipation. This article walks through the steps of calculating the power consumption and power dissipation of MOSFETS to provide electrical engineers, students and circuit designers with a clear thought of how to do the calculation under some complex circumstances. MOSFETS power consumption calculation is different under 3 different modes which are cutoff mode, saturation mode and triode mode. Under cutoff mode, the power consumption is zero. Under saturation mode, power consumption is calculated by MOSFETS consume certain amount of power and the total amount of power can be calculated by finding integral of the IV curve. For triode mode, power consumption can be determined by the equation derived later in the article. As for power dissipation, in this article, total power dissipation is divided into two parts which are switching power dissipation and resistive power dissipation. Then, each part of power dissipation is calculated by equations listed in the article and then added together which is the total power dissipation of MOSFETS.