is that the turn-off of an IGBT is considerably higher than its turn-on loss. Generally, in datasheets, turn-off energy is mentioned as a measured parameter; that number has to be multiplied with the switching frequency of the intended application in order to estimate the turn-off loss. At very high power levels, a thyristor-based device (e.g., a SCR, a GTO, a MCT, etc.) is still often used. This device can be turned on by a pulse provided by a driving circuit, but cannot be turned off by removing the pulse. A thyristor turns off as soon as no more current flows through it; this happens automatically in an alternating current system on each cycle, or requires a circuit with the means to divert current around the device. Both MCTs and GTOs have been developed to overcome this limitation, and are widely used in power distribution applications. A few applications of power semiconductors in switch mode include lamp dimmers, switch mode power supplies, induction cookers, automotive ignition systems, and AC and DC electric motor drives of all sizes. Amplifiers Amplifiers operate in the active region, where both device current and voltage are non-zero. Consequently power is continually dissipated and its design is dominated by the need to remove excess heat from the semiconductor device. Power amplifier devices can often be recognized by the heat sink used to mount the devices. Multiple types of power semiconductor amplifier device exist, such as the bipolar junction transistor, the vertical MOS field effect transistor, and others. Power levels for individual amplifier devices range up to hundreds of watts, and frequency limits range up to the lower microwave bands. A complete audio power amplifier, with two channels and a power rating on the order of tens of watts, can be put into a small integrated circuit package, needing only a few external passive components to function. Another important application for active-mode amplifiers is in linear regulated power supplies, when an amplifier device is used as a voltage regulator to maintain load voltage at a desired setting. While such a power supply may be less energy efficient than a switched mode power supply, the simplicity of application makes them popular, especially in current ranges up to about one amp. Parameters Breakdown voltage: Often, there is a trade-off between breakdown voltage rating and on-resistance, because increasing the breakdown voltage by incorporating a thicker and lower doped drift region leads