1. INSULATED GATE BIPOLAR TRANSISTOR (IGBT):
• IGBT (Insulated Gate Bipolar Transistor) is a three terminal power
switch having high input impedance and low on-state power loss
as in BJT (Bipolar Junction Transistor). Thus, IGBT is a combined
form of best qualities of both BJT and MOSFET.
• IGBT is a three-terminal device. The three terminals are Gate (G), Emitter (E)
and Collector (C). The circuit symbol of IGBT is shown below.
3. SEMICONDUCTOR CONTROLLED RECTIFIER (SCR) OR
THYRISTOR
A thyristor is a four-layer semiconductor device, consisting of
alternating P-type and N-type materials (PNPN). A thyristor
usually has three electrodes: an anode, a cathode and a gate,
also known as a control electrode.
symbol