During the turn-on transition, the high d v/d t of one transistor will affect the complementary transistor in a half-bridge configuration via the Miller capacitance, which may lead to a temporary shoot-through. However, the increased d i/d t and d v/d t will aggravate the parasitic effects due to the presence of parasitic components.ĭuring the turn-off transition, the high d i/d t will lead to a voltage overshoot due to the stray inductance.
The SiC metal–oxide–semiconductor field-effect transistor (MOSFET) can operate at a much faster switching speed than that of the Si insulated gate power transistor, thus allowing higher-frequency operation leading to smaller volume of passive components. Silicon carbide (SiC) has therefore been regarded as a promising successor to Si technology to push the existing operating limits of power converters. The power converters in applications such as electric vehicle (EV) /hybrid EV and more electric aircraft require the characteristics of high-power density and the ability to withstand high junction temperature. IET Generation, Transmission & Distribution.IET Electrical Systems in Transportation.IET Cyber-Physical Systems: Theory & Applications.IET Collaborative Intelligent Manufacturing.CAAI Transactions on Intelligence Technology.The high input case (logic 1) is trivial - the left "diode" is off and the current is diverted (steered) entirely through the right "diode" string. As a result, the base current of the input transistor is diverted ("steered") through the lower output part of the previous stage to ground and the circled transistor is off. The right diode is the string of three "diodes" in series: the base-collector junction of the input transistor, the base-emitter junction of the circled transistor and the base-emitter junction of Q2. The left diode is the base-emitter junction of the input transistor. Thus, at low input voltage (logical 0), there are two "diodes" in parallel. The base-emitter junctions of the circled transistor and the output transistor Q2 can be also considered as "diodes". The input transistor can be presented as two "diodes" ( base-emitter and base-collector junctions) with common anodes (the base). The input part of the TTL logic gate above can be easily explained at low input voltage (logic 0) by the phenomenon of current steering, the essence of which is: If we connect two diodes with different forward voltages in parallel, the current will flow through the diode with lower forward voltage.
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