Programming instructions

Diodes
Multisim Component Reference Guide 3-8 ni.com
3.4 LED (Light-Emitting Diode)
This diode emits visible light when forward current through it,
I
d
,
exceeds the turn-on current,
I
on
.
LEDs are used in the field of optoelectronics. Infrared devices are used together with
spectrally matched phototransistors in optoisolation couplers, hand-held remote controllers,
and in fiber-optic sensing techniques. Visible spectrum applications include status indicators
and dynamic power level bar graphs on a stereo system or tape deck.
3.4.1 Background Information
LEDs are constructed of gallium arsenide or gallium arsenide phosphide. While efficiency
can be obtained when conducting as little as 2 milliamperes of current, the usual design goal is
in the vicinity of 10 mA. During conduction, there is a voltage drop across the diode of about
2 volts.
Most early information display devices required power supplies in excess of 100 volts. The
LED ushered in an era of information display components with sizes and operating voltages
compatible with solid-state electronics. Until the low-power liquid-crystal display was
developed, LED displays were common, despite high current demands, in battery-powered
instruments, calculators and watches. They are still commonly used as on-board annunciators,
displays and solid-state indicator lamps.
FC Coefficient for forward-bias
depletion capacitance formula
0.5 -
TNOM Parameter measurement
temperature
27 °C
Symbol Parameter name Default Unit
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