Page 437 - Power Electronics Handbook

426 Glossary of terms
Inverter: A converter which changes d.c. input to a.c. output. The d.c.
may be derived from a battery, in which case forced commutation
components are required for the power switches if they are thyristors, or it
may be the d.c. energy from the load being fed back into an a.c. supply, as
when a.c. to d.c. converters are operating in an inversion mode. The
operating mode is now natural commutation.
ISM: Industrial, scientific and medical. Usually refers to a type of instrument
or an industrial application.
JFER Junction field effect transistor. A form of unipolar transistor capable
of operation in depletion mode only.
KGD: Known good die. A bare silicon die having the same level of quality
and reliability as a packaged device.
LASCR: Light activated silicon controlled rectifier. A thyristor which is
triggered by light instead of a gate current.
Latching current: The value of current needed to ensure that a thyristor
remains on once its gate drive has been removed.
Leakage current: The current which flows through a power semiconductor
when it is in the off state. This can flow either in the forward or reverse
direction, depending on the polarity of the voltage across the device.
Line commutation: See Natural commutation.
Mark-to-space control: Control of the amount of power delivered from a
d.c. source to a d.c. load by varying the ratio of the power switch open to
closed time in any cycle.
MCM: Multichip module. Assembly of several semiconductor chips
packaged as one unit.
MOSFER Metal oxide semiconductor field effect transistor. A form of
unipolar transistor capable of operation in enhancement or depletion
mode.
Natural commutation: The use of the energy available from the a.c. supply
to turn off the power semiconductors, usually in an a.c. to d.c. thyristor
converter operating in an inversion mode, or in a cycloconverter. This is
also known as line commutation.
Overlap angle: See Commutation angle.
Peak inverse voltage: The maximum value of the reverse voltage which can
be applied across a power semiconductor.
Phrrse control: A method for controlling the amount of power delivered to
the load by varying the delay angle. (See Way =$e.)
PLCC: Plastic leaded chip carrier. A surface mount integrated circuit
package.
Pulse number: The ratio of the number of output cycles to the input supply
frequency for an a.c. to d.c. converter.