POWER SEMICONDUCTOR
DEVICES
OVERVIEW
Historical
1
st
thyristor SCR developed in 1957
Since 1970, various type of power
electronic devices were developed
and become commercially available.
Power semiconductor Devices
Classification
Classification by materials (carrier type)
The two-terminal devices (diodes), whose state is
completely dependent on the external power circuit
they are connected to;
The three-terminal devices, whose state is not only
dependent on their external power circuit, but also
on the signal on their driving terminal (gate or
base). Transistors and thyristors belong to that
category.
A second classification is less obvious, but has a
strong influence on device performance: Some
devices are
majority carrier devices
(Schottky diode,
MOSFET),
while
the
others
are
minority
carrier
devices
(Thyristor, bipolar transistor, IGBT).
The former use only one type of charge carriers,
while the latter use both (i.e electrons and holes).
The majority carrier devices are faster, but the
charge injection of minority carrier devices allows
for better On-state performance
Common power devices
Some common power devices are the power diode,
thyristor, power MOSFET and IGBT. A power diode or
MOSFET operates on similar principles to its low-power
counterpart, but is able to carry a larger amount of current
and typically is able to support a larger reverse-bias voltage
in the off-state.
