LED Indication - Discrete

Part Number	Description / PDF	Quantity
LTL-307YE Lite-On, Inc.	LED YELLOW CLEAR T-1 3/4 T/H	81
LTL-4291N Lite-On, Inc.	LED ORANGE DIFFUSED T-1 T/H	14701
LTST-S220TBKT Lite-On, Inc.	LED BLUE CLEAR SMD R/A	81188
LTST-C190KFKT Lite-On, Inc.	LED ORANGE CLEAR CHIP SMD	4521
LTST-C171TGKT Lite-On, Inc.	LED GREEN CLEAR CHIP SMD	8844
LTST-C194TBKT Lite-On, Inc.	LED BLUE CLEAR SMD	310398
LTST-C190GKT Lite-On, Inc.	LED GREEN CLEAR CHIP SMD	132233
LTST-S310F2KT Lite-On, Inc.	LED RGB CLEAR SMD R/A	0
LTL2R3KSK Lite-On, Inc.	LED YELLOW CLEAR T-1 3/4 T/H	2827
LTST-C150KFKT Lite-On, Inc.	LED ORANGE CLEAR 1206 SMD	18269
LTST-C191KFKT Lite-On, Inc.	LED ORANGE CLEAR SMD	31731
LTST-C194TGKT Lite-On, Inc.	LED GREEN CLEAR SMD	801
LTL-307YLC Lite-On, Inc.	LED YELLOW DIFFUSED T-1 3/4 T/H	2098
LTST-C190KAKT Lite-On, Inc.	LED RED-ORANGE CLEAR CHIP SMD	23946
LTST-C930AKT Lite-On, Inc.	LED AMBER CLEAR CHIP SMD	1315
LTL2T3TGK6 Lite-On, Inc.	LED GREEN CLEAR T-1 3/4 T/H	6740
LTST-C190KRKT Lite-On, Inc.	LED RED CLEAR CHIP SMD	0
LTST-C170EKT Lite-On, Inc.	LED RED CLEAR SMD	82189
LTW-2R3D7 Lite-On, Inc.	LED WHITE CLEAR T-1 3/4 T/H	22501
LTST-S220YKT Lite-On, Inc.	LED YELLOW CLEAR SMD R/A	5606

LED Indication - Discrete

1. Overview

Discrete Light Emitting Diodes (LEDs) are single-chip optoelectronic devices that convert electrical energy into light through electroluminescence. This product category forms the foundation of modern indication systems, offering advantages including low power consumption, long lifespan, and high reliability. Their importance spans across consumer electronics, industrial equipment, automotive systems, and communication infrastructure.

2. Major Types and Functional Classification

Type	Functional Characteristics	Application Examples
Visible LEDs	Emits light in visible spectrum (400-700nm), available in multiple colors	Indicator lamps, display backlighting, decorative lighting
Infrared LEDs	Emits 700nm-1mm wavelength radiation, invisible to human eye	Remote controls, security sensors, night vision systems
High-Brightness LEDs	Enhanced luminous intensity (>1000mcd) with advanced packaging	Automotive lighting, outdoor displays, emergency signage
UV LEDs	Ultraviolet spectrum emission (280-400nm)	Sterilization equipment, counterfeit detection, curing systems

3. Structure and Composition

Typical discrete LED construction includes:

Die: Semiconductor chip (GaN/InGaN for blue/green, AlGaInP for red)
Encapsulation: Epoxy or silicone lens for light extraction and protection
Lead Frame: Copper or iron alloy for electrical connection and heat dissipation
Phosphor Coating: Used in white LEDs for wavelength conversion
Reflective Cup: Optimizes light directionality

4. Key Technical Parameters

Parameter	Significance	Typical Range
Wavelength	Determines light color and application suitability	375nm-940nm
Luminous Intensity	Measures brightness output (mcd)	50-10,000mcd
Forward Current	Operating current rating	20-150mA
Forward Voltage	Electrical potential drop	1.8-3.6V
Viewing Angle	Light emission spread measurement	5 -120

5. Application Fields

Primary application sectors include:

Consumer Electronics: Mobile phone indicators, keyboard backlighting
Automotive: Dashboard indicators, brake light systems
Industrial: Machine status indicators, safety signage
Medical: Diagnostic equipment indicators, phototherapy devices
Telecommunications: Network equipment status lights

6. Leading Manufacturers and Products

Manufacturer	Product Series	Key Features
Cree Inc.	XLamp XP-G3	High brightness (3200mcd), 120 viewing angle
OSRAM Opto	OSTAR Projection	High-power LED for automotive lighting
Nichia Corp.	NSHU5991	UV LED (365nm) for curing applications
Everlight Electronics	LTST-C19HE8WT	Tri-color LED for RGB indication

7. Selection Recommendations

Key consideration factors:

Spectral Requirements: Match wavelength to application needs
Environmental Conditions: Temperature range (-40 C to +85 C typical)
Power Constraints: Select appropriate current/voltage ratings
Optical Design: Consider lens type and viewing angle
Reliability: Check MTTF (Mean Time to Failure) specifications

Industry Development Trends

Current technology directions include:

Miniaturization: Development of micro-LED ( LED) with dimensions <50 m
Efficiency Improvement: Targeting >300lm/W efficacy for visible LEDs
Smart Integration: Incorporating driver ICs and sensors in LED packages
Material Innovation: GaN-on-silicon substrates for cost reduction
Regulatory Compliance: RoHS/REACH compliant packaging materials