01․ A GTO can be turned on by applying
Gate turn off (GTO), like an SCR is a device four layer, three junction semiconductor device with three external terminal (anode, cathode and gate). GTO can be turned on and off by positive pulse or signal and negative pulse or signal respectively to the gate terminal.
02․ SITH is also known as
They static induction thyristor (SITHs) is a thystor with a buried gate structure in which the gate electrodes are placed in n-base region. They are normally on-state, gate electrodes must be negatively biased to hold off-state. It is a self controlled GTO like device. Hence it is sometimes called field controlled diode.
03․ The reverse recovery time of diode is trr = 3 μs and the rate off all of the diode current is di/dt = 30 A/μs. The storage charge current QRR is
04․ The turn-on time of an SCR with inductive load is 20 µs. The puls train frequency is 2.5 KHz with a mark/space ratio of 1/10, then SCR will
Pulse repetition rate (PRR) = 1/(2.5 - 103) = 0.4 ms = 400 µs.
Mark/space ratio = 1/10.
Pulse width = 400/11 = 36.4 µs.
The SCR will turn on because the pulse width is more than SCR turn on time.
05․ A power MOSFET has three terminals called
A power MOSFET has three terminals called drain, source and gate in place corresponding three terminals collector, emitter and base base for BJT.
06․ A modern power semiconductor device that combines the characteristic of BJT and MOSFET is
IGBT process high input input impedance like a MOSFET and has on state power loss as in a BJT.
07․ Which one is most suitable power device for high frequency (>100 KHz) switching application?
Power MOSFET has low turn off time. So it can be operated in a frequency range of 1 to 10 MHz.
08․ Thermal voltage VT can be given by
The thermal voltage is given by
VT = Kq/T
Where, q = electron change, T = absolute temperature, K = Boltzman Constant.
09․ IGBT combines the advantages of
IGBT combines the advantage of BJTs and MOSFETs. IGBT process high input impedance like a MOSFET and has low on state power loss as in a BJT.
10․ COOLMOS device can be used in application up to power range of
COOLMOS used in application up to power range of 2 KVA.
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