Orange SMD LED LTST-M670KFKT Datasheet - AlInGaP Material - 120° Viewing Angle - 20mA - Technical Documentation

1. Product Overview

This document provides the complete technical specifications for a Surface-Mount Device (SMD) Light-Emitting Diode (LED). This device is an orange LED that uses Aluminum Indium Gallium Phosphide (AlInGaP) semiconductor material as its light source, encapsulated within a transparent lens. It is specifically designed for automated assembly processes, is compatible with infrared reflow soldering technology, and is suitable for high-volume production of Printed Circuit Boards (PCB). This product complies with the RoHS (Restriction of Hazardous Substances) directive and is an environmentally friendly product.

1.1 Core Advantages and Target Market

The primary advantages of this LED include its compatibility with automated pick-and-place equipment, which simplifies the production process; and its compliance with lead-free infrared reflow soldering requirements, aligning with modern environmental and manufacturing standards. Its EIA (Electronic Industries Alliance) standard package ensures mechanical compatibility with industry-standard mounting systems. The device is also described as being compatible with integrated circuits (I.C.), indicating its driving characteristics are suitable for direct interfacing with typical logic-level outputs. Its target applications are broad, covering general-purpose electronic equipment requiring reliable indicator lighting.

2. Detailed Technical Parameters

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. They are specified at an ambient temperature (Ta) of 25°C.

• Power Dissipation (Pd):72 mW. This is the maximum power the device can dissipate in the form of heat without exceeding its thermal limits.
• Peak Forward Current (IFP):80 mA. This is the maximum allowable instantaneous forward current, typically specified under pulse conditions (1/10 duty cycle, 0.1ms pulse width) to prevent overheating.
• DC Forward Current (IF):30 mA. This is the maximum continuous forward current that can be applied to the LED under steady-state conditions.
• Reverse Voltage (VR):5 V. Applying a reverse voltage exceeding this value may cause breakdown and damage the LED junction.
• Operating Temperature Range:-40°C to +85°C. This is the ambient temperature range over which the device is guaranteed to operate within its specified parameters.
• Storage Temperature Range:-40°C to +100°C. This is the safe storage temperature range when the device is not powered.

2.2 Electrical and Optical Characteristics

These are typical performance parameters, measured under conditions of Ta=25°C and test current (IF)=20 mA, unless otherwise specified.

• Luminous Intensity (Iv):The range is from a minimum of 140 mcd to a typical maximum of 450 mcd. This is the perceived brightness of the LED as measured using a filter approximating the CIE photopic response curve.
• Viewing Angle (2θ1/2):120 degrees. This is the full angle at which the luminous intensity drops to half of the measurement on the central axis (0°). A 120° angle indicates a wide viewing angle pattern.
• Peak Emission Wavelength (λP):611 nm. This is the wavelength at which the LED's spectral power output reaches its maximum value.
• Dominant Wavelength (λd):Ranges from 600 nm to 612 nm. This is derived from the CIE chromaticity diagram and represents the single wavelength that best describes the perceived color of the light. It is a key parameter for color specification.
• Spectral Line Half-Width (Δλ):17 nm. This is the width of the emission spectrum at half of its maximum power (Full Width at Half Maximum - FWHM). For AlInGaP orange LEDs, 17nm is a typical value, indicating a relatively pure color.
• Forward Voltage (VF):At IF=20mA, the range is from 1.8 V to 2.4 V. This is the voltage drop across the LED when the forward current is applied.
• Reverse Current (IR):At VR=5V, the maximum is 10 μA. This is the small leakage current that flows when the specified reverse voltage is applied.

3. Explanation of the Grading System

To ensure production consistency, LEDs are sorted into different bins based on key parameters. This allows designers to select devices that meet specific color and electrical performance requirements.

3.1 Forward Voltage Grading (Unit: V @20mA)

LEDs are classified according to their forward voltage drop:
Bin Code D2: 1.8V (Min) to 2.0V (Max)
Bin Code D3: 2.0V (Min) to 2.2V (Max)
Gear code D4: 2.2V (min) to 2.4V (max)
The tolerance for each gear is +/-0.1V.

3.2 Luminous Intensity Binning (Unit: mcd @20mA)

LEDs are sorted according to their brightness output:
Gear code R2: 140.0 to 180.0 mcd
Gear code S1: 180.0 to 224.0 mcd
Gear code S2: 224.0 to 280.0 mcd
Gear code T1: 280.0 to 355.0 mcd
Gear code T2: 355.0 to 450.0 mcd
Kowane matakin yana da ƙarancin +/-11%.

3.3 Dominant Wavelength Binning (Unit: nm @20mA)

LED ana rarrabe su bisa daidaitaccen launinsu (babban tsayin raƙuman ruwa):
Lambar matakin P: 600.0 zuwa 603.0 nm
Gear code Q: 603.0 to 606.0 nm
Gear code R: 606.0 to 609.0 nm
Gear code S: 609.0 to 612.0 nm
The tolerance for each gear is +/- 1nm.

4. Performance Curve Analysis

The datasheet references typical characteristic curves, which are crucial for understanding the device's behavior under various conditions. Although the specific graphs are not reproduced in the text, an analysis of their meaning follows.

4.1 Forward Current vs. Forward Voltage (I-V Curve)

The I-V curve of an LED is exponential. For a forward voltage range specified as 1.8V to 2.4V at 20mA, designers can expect the operating point to fall within this window. This curve helps in selecting an appropriate current-limiting resistor and understanding the voltage requirements of the drive circuit.

4.2 Luminous Intensity vs. Forward Current

This curve typically shows that luminous intensity increases with forward current, but not necessarily in a linear fashion, especially as the current approaches the maximum rated value. This is crucial for determining the drive current required to achieve the desired brightness level.

4.3 Temperature Characteristics

Aikin LED yana da alaƙa da zafin jiki. Yawanci, ƙarfin lantarki na gaba yana raguwa tare da haɓakar zafin haɗin gwiwa, yayin da ƙarfin haske kuma yana raguwa. Fahimtar waɗannan lanƙwasan yana da mahimmanci ga aikace-aikacen da ke aiki a cikin kewayon zafin jiki daga -40°C zuwa +85°C, don tabbatar da daidaiton aiki.

4.4 Spectral Distribution

The spectral output curve shows the light intensity emitted at different wavelengths, centered at a peak wavelength of 611nm with a half-width of 17nm. This defines the color purity of the orange light.

5. Mechanical and Packaging Information

5.1 Device Package Dimensions

This LED is supplied in a standard SMD package. The datasheet contains a detailed dimensional drawing, with all critical dimensions provided in millimeters (and inches). Key dimensions include body length, width, height, lead pitch, and pad recommendations. Unless otherwise specified, tolerances are typically ±0.2mm. This information is crucial for PCB pad pattern design.

5.2 Polarity Marking

SMD LED must be correctly oriented on the PCB. The datasheet drawing indicates the cathode (negative) and anode (positive) terminals by a mark or an asymmetric feature on the package body.

5.3 Tape and Reel Packaging

For automated assembly, LEDs are supplied in embossed carrier tape and reel format.
Carrier Tape Dimensions:Carrier tape width, pocket dimensions, and cover tape specifications are provided to ensure feeder compatibility.
LED e wa ni a 7-inch (178mm) diameter reel. Reel kowane yana dauke da 2000 guda. Rago na sauran sassan shine 500 guda. Kunshin ya bi ka'idojin ANSI/EIA-481. Bayanin cewa an rufe wuraren da ba kowa, ana ba da izinin rasa abubuwa biyu a jere.Reel Specification:

6. Soldering and Assembly Guide

6.1 Infrared Reflow Soldering Profile

This device is compatible with infrared reflow soldering processes. A recommended profile compliant with J-STD-020B lead-free soldering requirements is provided. Key parameters of this profile include:
Preheating:150-200°C.
Preheating time:Maximum 120 seconds.
Peak temperature:Maximum 260°C.
Time Above Liquidus:Critical for forming a good solder joint (refer to the graph on page 3 for specific time).
The curve is a general target; the final board-level curve should be characterized based on the specific PCB design, solder paste, and reflow oven used.

6.2 Manual Soldering (Electric Soldering Iron)

If hand soldering is required, the following restrictions apply:
Soldering iron temperature:Maximum 300°C.
Soldering time:Maximum 3 seconds per solder joint.
Manual soldering should be performed only once to avoid thermal stress.

6.3 Cleaning

If cleaning is required after soldering, only specified solvents should be used. It is recommended to immerse the LED in ethanol or isopropanol at room temperature for no more than one minute. Unspecified chemicals may damage the package.

6.4 Storage Conditions

Proper storage is crucial for maintaining solderability, especially for moisture-sensitive components.
Sealed Packaging:Store at ≤30°C and ≤70% relative humidity (RH). When stored in the original moisture barrier bag with desiccant, the shelf life is one year.
Opened package:For components removed from the sealed bag, the storage environment should not exceed 30°C and 60% RH. It is recommended to complete infrared reflow soldering within 168 hours (7 days) after exposure. For longer storage, components should be kept in a sealed container with desiccant or a nitrogen dry box. Components exposed for more than 168 hours should be baked at approximately 60°C for at least 48 hours before assembly to remove absorbed moisture and prevent the "popcorn" effect during reflow.

7. Application Suggestions and Design Considerations

7.1 Typical Application Circuit

LED is a current-driven device. The most common driving method is to use a series current-limiting resistor. The resistor value (R) is calculated using Ohm's law: R = (Vcc - VF) / IF, where Vcc is the supply voltage, VF is the LED forward voltage (for reliability, use the maximum value from the binning or datasheet), and IF is the desired forward current (e.g., 20mA). For multiple LEDs, connecting them in series ensures the same current flows through each LED, promoting uniform brightness. Parallel connection without individual resistors is not recommended, as slight variations in VF can lead to significant current imbalance.

7.2 PCB Pad Design (Pad Pattern)

The datasheet provides recommended pad layouts for infrared or vapor phase reflow soldering. Following this recommendation is crucial for achieving reliable solder joints, proper alignment, and minimizing tombstoning. The pad design takes thermal mass and solder volume into account.

7.3 Thermal Management

Although the power consumption is relatively low (maximum 72mW), good thermal design on the PCB helps maintain a lower junction temperature, thereby improving luminous efficiency and long-term reliability. This may involve the use of thermal vias or ensuring sufficient copper area connected to the LED pads.

7.4 Application Scope and Precautions

This LED is suitable for general electronic equipment, such as office equipment, communication equipment, and household appliances. For applications requiring extremely high reliability where failure could endanger life or health (e.g., aviation, medical systems, security equipment), specialized consultation and certification are required prior to use.

8. Technical Comparison and Differentiation

This AlInGaP orange LED offers specific advantages. Compared to older technologies, AlInGaP provides higher efficiency and better color stability over time and with temperature changes. For SMD indicator LEDs, the 120-degree viewing angle is very wide, offering good off-axis visibility. Its compatibility with standard lead-free infrared reflow soldering profiles makes it an environmentally friendly choice suitable for modern production lines. The comprehensive binning structure allows for precise selection based on color and brightness requirements, which is crucial for applications requiring visual consistency across multiple indicators.

9. Frequently Asked Questions (Based on Technical Parameters)

Q: At what current should I drive this LED?
A: Typical test condition is 20mA, maximum continuous current is 30mA. For general indication purposes and good service life, driving at 20mA is standard practice. Be sure to use a series current-limiting resistor.

Q: How to understand the luminous intensity value?
A: Luminous intensity (mcd) is a measure of brightness in a specific direction. The range of 140-450 mcd at 20mA, combined with a 120° viewing angle, means it will appear bright when viewed on-axis and remain visible over a wide area.

Q: Can I use this LED outdoors?
A: The operating temperature range of -40°C to +85°C indicates it can withstand a wide range of environmental conditions. However, the package is not specifically rated for waterproofing or UV resistance. For outdoor use, additional environmental protection (such as conformal coating, enclosures) is required.

Q: Why are storage conditions so important?
A: SMD packages absorb moisture from the air. If a moisture-laden component is subjected to the high temperatures of reflow soldering, the rapid vaporization of the moisture can cause internal delamination or cracking (the "popcorn" effect), leading to failure. Adhering to storage and baking guidelines prevents this.

10. Practical Design and Usage Cases

Scenario: Designing a status indicator panel for a network router.
This panel requires multiple orange LEDs to indicate different link and activity statuses. Consistency in color and brightness is important for the user experience.
Design Steps:
1. Grade Selection:Specify the bin for dominant wavelength (e.g., bin R: 606-609nm) and luminous intensity (e.g., bin T1: 280-355 mcd) to ensure all LEDs on the panel appear uniform.
2. Circuit Design:The router's logic supply is 3.3V. Using a maximum VF of 2.4V (from bin D4) and a target IF of 20mA, calculate the series resistor: R = (3.3V - 2.4V) / 0.020A = 45 ohms. A standard 47-ohm resistor will be used.
3. PCB Layout:Use the pad dimensions recommended in the datasheet. When placing LEDs, allow sufficient spacing for a wide 120° viewing angle to prevent optical crosstalk.
4. Assembly:Ensure the factory follows the provided J-STD-020B reflow profile. Verify that components taken from opened reels are used within 168 hours or properly baked.
5. Result:A panel with a consistent brightness and uniform color orange indicator, clearly visible from various angles.

11. Introduction to Working Principles

A light-emitting diode is a semiconductor device that emits light through electroluminescence. When a forward voltage is applied across the p-n junction, electrons from the n-type material recombine with holes from the p-type material in the active region. This recombination releases energy in the form of photons (light). The specific wavelength (color) of the emitted light is determined by the bandgap energy of the semiconductor material used. In this device, the bandgap of the AlInGaP (aluminum indium gallium phosphide) compound semiconductor corresponds to orange light, with a dominant wavelength in the range of 600-612 nm. A transparent epoxy resin lens encapsulates the semiconductor chip, providing mechanical protection and shaping the light output to achieve the specified 120-degree viewing angle.

12. Technology Trends

Ci gaban fasahar LED yana ci gaba da mayar da hankali kan wasu mahimman fagage masu alaƙa da irin waɗannan LED na nuni. Haɓaka inganci (ƙarin fitowar haske a kowace raka'a na shigar da wutar lantarki) wani ci gaba ne mai ci gaba, wanda zai iya ba da damar samun haske iri ɗaya a ƙarƙashin ƙaramin ƙarfin tuƙi, don haka rage amfani da wutar lantarki da zafi. Ci gaban kayan marufi yana nufin haɓaka dogon lokaci na aminci da kwanciyar hankali na launi a cikin yanayin zafi da zafi mai girma. Ƙarin ƙaramin girma na marufi kuma wani salo ne yayin da ake kiyayewa ko inganta aikin gani. Bugu da ƙari, haɗa kayan lantarki na tuƙi ko ayyukan sarrafawa (kamar daidaita halin yanzu na ciki ko PWM dimming) kai tsaye cikin marufin LED, wani ci gaba ne don ƙarin aikace-aikacen nuni masu haɓaka, wanda ke sauƙaƙa ƙirar kewaye na mai amfani na ƙarshe.