Side Looking SMD LED LTST-S110TGKT Datasheet - Package Dimensions - Forward Voltage 3.2V - Luminous Intensity up to 450mcd - Green 530nm - English Technical Document

1. Product Overview

This document provides comprehensive technical specifications for a side-looking surface-mount device (SMD) LED. The component is designed for applications requiring a wide viewing angle and high brightness from a compact, side-emitting package. It utilizes an InGaN (Indium Gallium Nitride) semiconductor chip to produce green light, offering a balance of efficiency and performance suitable for modern electronic assemblies.

The LED is packaged on 8mm tape wound onto 7-inch diameter reels, making it fully compatible with high-speed automated pick-and-place equipment used in volume manufacturing. Its design adheres to EIA (Electronic Industries Alliance) standard packaging, ensuring broad compatibility within the industry.

2. Technical Parameter Deep Dive

2.1 Absolute Maximum Ratings

The absolute maximum ratings define the stress limits beyond which permanent damage to the device may occur. These values are specified at an ambient temperature (Ta) of 25°C and should not be exceeded under any operating conditions.

• Power Dissipation (Pd): 76 mW. Wannan shine matsakaicin adadin wutar da fakitin LED zai iya watsawa a matsayin zafi ba tare da wuce iyakokin zafinsa ba.
• Peak Forward Current (IFP): 100 mA. This is the maximum allowable instantaneous forward current, typically specified under pulsed conditions (1/10 duty cycle, 0.1ms pulse width) to prevent overheating the chip.
• DC Forward Current (IF): 20 mA. This is the recommended maximum continuous forward current for reliable long-term operation.
• Operating Temperature Range: -20°C to +80°C. The device is guaranteed to function within this ambient temperature range.
• Storage Temperature Range: -30°C to +100°C. The device can be stored without degradation within these limits.
• Infrared Reflow Soldering Condition: 260°C peak temperature for a maximum of 10 seconds. This defines the thermal profile tolerance for lead-free (Pb-free) solder assembly processes.

2.2 Electrical & Optical Characteristics

The typical operating characteristics are measured at Ta=25°C with a forward current (IF) of 20 mA, unless otherwise noted. These parameters define the expected performance under normal use.

• Luminous Intensity (Iv): Ranges from a minimum of 71.0 mcd to a maximum of 450.0 mcd. The intensity is measured using a sensor filtered to match the CIE photopic (human eye) response curve. The actual value for a specific unit depends on its bin code (see Section 3).
• Viewing Angle (2θ1/2): Digiri 130. Wannan shine cikakken kusurwar da ƙarfin haske ya ragu zuwa rabin ƙimarsa a tsakiyar axis (0°). Faɗin kusurwar kallo na 130° ya sa wannan LED ya dace da amfani da hasken baya da alamomin nuni inda ake buƙatar ganin haske daga gefe.
• Peak Emission Wavelength (λP): 530 nm. This is the wavelength at which the spectral power output of the LED is at its maximum.
• Dominant Wavelength (λd): 525 nm. This is derived from the CIE chromaticity diagram and represents the single wavelength that best describes the perceived color of the light emitted. It is a more accurate representation of color than peak wavelength.
• Spectral Line Half-Width (Δλ): 35 nm. This parameter indicates the spectral purity or bandwidth of the emitted light, measured as the full width at half maximum (FWHM) of the emission spectrum.
• Forward Voltage (VF): Typically 3.20 V, with a range from 2.80 V (Min) to 3.60 V (Max) at IF=20mA. This is the voltage drop across the LED when operating.
• Reverse Current (IR): 10 μA (Max) when a reverse voltage (VR) of 5V is applied. It is critical to note that this LED is not designed for operation in reverse bias; this test condition is for leakage current characterization only.

3. Binning System Explanation

To ensure consistency in mass production, LEDs are sorted into performance bins based on key parameters. This allows designers to select parts that meet specific requirements for color, brightness, and voltage.

3.1 Forward Voltage Binning

Units are categorized by their forward voltage (VF) at 20mA. The tolerance within each bin is +/-0.1V.

• Bin D7: VF = 2.80V - 3.00V
• Bin D8: VF = 3.00V - 3.20V
• Bin D9: VF = 3.20V - 3.40V
• Bin D10: VF = 3.40V - 3.60V

3.2 Luminous Intensity Binning

Units are sorted by their luminous intensity (Iv) at 20mA. The tolerance within each bin is +/-15%.

• Bin Q: Iv = 71.0 mcd - 112.0 mcd
• Bin R: Iv = 112.0 mcd - 180.0 mcd
• Bin S: Iv = 180.0 mcd - 280.0 mcd
• Bin T: Iv = 280.0 mcd - 450.0 mcd

3.3 Dominant Wavelength Binning

Units are categorized by their dominant wavelength (λd) at 20mA. The tolerance within each bin is +/-1nm, ensuring tight color consistency.

• Bin AP: λd = 520.0 nm - 525.0 nm
• Bin AQ: λd = 525.0 nm - 530.0 nm
• Bin AR: λd = 530.0 nm - 535.0 nm

Selecting from specific bins allows for precise color matching and brightness uniformity in multi-LED applications, such as displays or backlight arrays.

4. Performance Curve Analysis

While specific graphical curves are referenced in the datasheet (e.g., Figure 1 for spectral distribution, Figure 5 for viewing angle), their typical implications are analyzed here. These curves are essential for understanding device behavior under varying conditions.

Forward Current vs. Luminous Intensity (I-Iv Curve): The luminous intensity of an LED is directly proportional to the forward current, typically following a near-linear relationship within the recommended operating range. Exceeding the maximum DC current will not only increase brightness non-linearly but also generate excessive heat, potentially reducing lifespan and shifting the dominant wavelength.

Forward Current vs. Forward Voltage (I-V Curve): The I-V characteristic of an LED is exponential. A small increase in voltage beyond the typical forward voltage (e.g., 3.2V) can cause a large, potentially damaging increase in current if not properly current-limited by a driver circuit or series resistor.

Temperature Dependence: LED performance is temperature-sensitive. As the junction temperature increases:

• Luminous Intensity decreases. Higher temperatures cause reduced internal quantum efficiency, leading to lower light output for the same drive current.
• Forward Voltage decreases. The semiconductor's bandgap narrows slightly with temperature, reducing the voltage required to achieve a given current.
• Dominant Wavelength shifts. Typically, for InGaN-based green LEDs, the wavelength may shift slightly to longer wavelengths (red shift) as temperature rises, affecting color perception.

These factors underscore the importance of proper thermal management in PCB design.

5. Mechanical & Packaging Information

5.1 Package Dimensions

The LED features a side-looking SMD package. All critical dimensions, including body length, width, height, and lead positions, are provided in the datasheet drawings with a general tolerance of ±0.10 mm (0.004"). This precision ensures reliable placement and soldering by automated machinery.

5.2 Soldering Pad Layout & Polarity

Datasheet ya ƙunshi shawarar ƙafar ƙafar soldering don shimfidar PCB. Bin waɗannan shawarwari yana da mahimmanci don samun haɗin gwiwa mai dogaro da daidaitawar da ta dace. Kayan yana da alamar polarity (yawanci alamar cathode akan jikin fakiti). Dole ne a kiyaye daidaitaccen yanayin yayin haɗawa, saboda amfani da ƙarfin lantarki na baya zai iya lalata LED nan take.

5.3 Tape and Reel Specifications

Ana ba da na'urar akan tef ɗin ɗaukar kaya mai zane tare da tef ɗin kariya, wanda aka nannade akan reels mai diamita 7-inch (178 mm). Matsakaicin adadin reel shine guda 3000. Muhimman ƙayyadaddun tef sun haɗa da filin aljihu, faɗin tef, da girmam reels, waɗanda aka ƙera don su yi daidai da ka'idodin ANSI/EIA-481-1-A don kayan aikin sarrafawa ta atomatik.

6. Soldering & Assembly Guidelines

6.1 Reflow Soldering Profile

A suggested infrared (IR) reflow profile for lead-free (Pb-free) solder processes is provided. Key parameters include:

• Pre-heat Zone: 150°C to 200°C, with a maximum pre-heat time of 120 seconds to gradually heat the board and components, activating the flux and minimizing thermal shock.
• Peak Temperature: Maximum of 260°C. The component must not be exposed to temperatures above this limit.
• Time Above Liquidus (TAL): The time within which the solder is molten is critical for joint formation. The profile suggests a maximum of 10 seconds at peak temperature, and reflow should not be performed more than twice.

This profile is based on JEDEC standards and serves as a generic target; final profiles should be validated for specific PCB designs, solder pastes, and oven characteristics.

6.2 Hand Soldering

If hand soldering is necessary, extreme care must be taken:

• Iron Temperature: Maximum 300°C.
• Soldering Time: Maximum 3 seconds per solder joint.
• Frequency: Should be performed only once to avoid thermal stress on the plastic package and the internal wire bonds.

6.3 Cleaning

If post-solder cleaning is required, only specified solvents should be used to avoid damaging the LED's plastic lens and package. Recommended cleaning agents are alcohol-based, such as ethyl alcohol or isopropyl alcohol (IPA). The LED should be immersed at normal room temperature for less than one minute. Harsh or unspecified chemical cleaners must be avoided.

6.4 Matakan Kariya daga Zubar da Wutar Lantarki (ESD)

LEDs are sensitive to electrostatic discharge (ESD) and electrical surges. Handling precautions are mandatory:

• Yi amfani da grounded wrist strap ko anti-static gloves lokacin da ake sarrafa na'urori.
• Tabbatar cewa duk workstations, kayan aiki, da kayan aikin suna da ingantaccen tushe.
• Ajiye da kuma jigilar kayan a cikin ESD-protective packaging.

7. Storage & Handling Conditions

Proper storage is vital to maintain solderability and device reliability, especially for moisture-sensitive SMD packages.

• Sealed Package: LEDs in their original, unopened moisture-barrier bag (with desiccant) should be stored at ≤30°C and ≤90% relative humidity (RH). The recommended shelf life under these conditions is one year.
• Opened Package: Once the moisture barrier bag is opened, the storage environment should not exceed 30°C and 60% RH. It is strongly recommended to complete the IR reflow soldering process within one week of opening.
• Extended Storage (Opened): For storage beyond one week, components should be placed in a sealed container with fresh desiccant or in a nitrogen-purged desiccator.
• Baking: If components have been exposed to ambient conditions for more than one week, a baking process (approximately 60°C for at least 20 hours) is recommended prior to soldering to remove absorbed moisture and prevent "popcorning" (package cracking) during reflow.

8. Application Suggestions

8.1 Typical Application Scenarios

The side-looking emission profile and wide viewing angle make this LED ideal for several applications:

• Status Indicators on Vertical Panels: Perfect for equipment where the PCB is mounted perpendicular to the user's line of sight, such as in networking hardware, audio mixers, or industrial control panels.
• Edge-Lit Backlighting: Ana iya amfani da shi don haskaka jagororin haske a cikin ƙananan nuni, maɓallan maɓalli, ko bangon ado daga gefe, yana haifar da haske iri ɗaya.
• Consumer Electronics: Indicator lights in smartphones, tablets, laptops, gaming consoles, and home appliances.
• Automotive Interior Lighting: For non-critical interior status lights, provided the operating temperature and reliability requirements are met.

8.2 Design Considerations

• Current Limiting: Always drive the LED with a constant current source or a current-limiting resistor in series. The resistor value can be calculated using the formula: R = (Vsupply - VF) / IF, where VF is the typical or maximum forward voltage from the datasheet to ensure safe operation under all conditions.
• Thermal Management: Although power dissipation is low (76 mW), ensuring adequate copper area around the solder pads on the PCB helps dissipate heat, maintaining LED performance and longevity, especially in high ambient temperatures or enclosed spaces.
• Optical Design: Consider the 130° viewing angle when designing light pipes, lenses, or diffusers to effectively capture and direct the emitted light.
• ESD Protection: In applications prone to ESD events, consider adding transient voltage suppression (TVS) diodes or other protection circuitry on the LED driver lines.

9. Technical Comparison & Differentiation

Compared to standard top-emitting SMD LEDs, this side-looking variant offers a distinct advantage in applications where board space is limited on the top surface or where light needs to be directed horizontally. Its key differentiators include:

• Emission Direction: Primary light output is from the side of the package, not the top.
• Wide Viewing Angle: The 130° viewing angle is typically wider than many top-emitting LEDs, providing a broader field of visibility.
• Compatibility: Maintains full compatibility with standard SMD assembly processes (reflow soldering, pick-and-place), unlike some specialized side-emitters that may require manual assembly.
• InGaN Technology: The use of InGaN for green light offers higher efficiency and better performance stability compared to older technologies like AlInGaP for certain green wavelengths.

10. Frequently Asked Questions (FAQ)

10.1 What is the difference between Peak Wavelength and Dominant Wavelength?

Peak Wavelength (λP) shine kawai tsayin raƙuman ruwa inda LED ke fitar da mafi yawan ƙarfin haske. Dominant Wavelength (λd) is calculated from the CIE color coordinates and represents the perceived color. For monochromatic LEDs like this green one, they are often close, but λd is the more relevant parameter for color specification in human-centric applications.

10.2 Ina iya tuka wannan LED ba tare da resistor mai iyakancewar halin yanzu ba?

No. The forward voltage of an LED has a negative temperature coefficient and varies from unit to unit (as shown in the binning). Connecting it directly to a voltage source, even one matching its typical VF, will result in uncontrolled current flow, likely exceeding the absolute maximum rating and destroying the device instantly. A series resistor or constant-current driver is mandatory.

10.3 Me ya sa akwai tsarin binning, kuma wane bin ne ya kamata in zaɓi?

The binning system accounts for natural variations in semiconductor manufacturing. It allows you to select parts that meet your specific needs:

• Choose a specific Dominant Wavelength bin (AP, AQ, AR) for strict color consistency across multiple LEDs in a display.
• Zabi mafi girma Luminous Intensity bin (S, T) idan haske mafi girma shine fifiko.
• Choose a specific Forward Voltage bin (D7-D10) if designing for very precise power supply voltage margins.

For most general applications, specifying a range (e.g., Bin AQ for color, Bin R or S for intensity) is sufficient and cost-effective.

10.4 How do I interpret the "260°C for 10 seconds" soldering condition?

This means that during the reflow soldering process, the temperature measured at the LED's leads or package body should not exceed 260°C. Furthermore, the duration for which the temperature is at or near this peak (typically within 5-10°C of the peak) should not exceed 10 seconds. Exceeding these limits can damage the plastic package, the internal die attach, or the wire bonds.

11. Practical Design Case Study

Scenario: Designing a status indicator for a portable medical device. The PCB is mounted vertically inside a slim enclosure. The indicator must be clearly visible from a wide angle and exhibit consistent green color.

Implementation:

1. Component Selection: This side-looking LED is chosen. To ensure color consistency, the design specifies Bin AQ (525-530nm Dominant Wavelength). For adequate brightness, Bin S (180-280 mcd) is selected.
2. Circuit Design: The device is powered by a 5V system rail. A series resistor is calculated using the maximum VF from the datasheet for safety: R = (5V - 3.6V) / 0.020A = 70 Ohms. The nearest standard value of 68 Ohms is selected, resulting in a current of approximately (5V - 3.2V)/68Ω ≈ 26.5mA, which is slightly above the typical 20mA but still within the absolute maximum DC current rating. A small-signal MOSFET can be added for microcontroller control.
3. PCB Layout: The suggested soldering pad layout from the datasheet is used. Additional thermal relief copper pours are added to the cathode and anode pads to aid heat dissipation without making hand rework difficult.
4. Optical Integration: A simple, molded plastic light pipe is designed to channel the side-emitted light to a small aperture on the front panel of the device. The 130° viewing angle of the LED ensures efficient coupling into the light pipe.
5. Assembly: The LEDs are kept in their sealed bags until just before use. The assembled PCB undergoes reflow soldering using a validated profile that stays within the 260°C for 10 seconds limit.

This approach results in a reliable, consistent, and bright status indicator suitable for the application.

12. Technology Principle Introduction

This LED is based on InGaN (Indium Gallium Nitride) semiconductor technology. The core principle is electroluminescence. When a forward voltage is applied across the p-n junction of the semiconductor, electrons from the n-type region and holes from the p-type region are injected into the active region (the quantum well). There, electrons recombine with holes, releasing 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, which in turn is controlled by the precise composition of the InGaN alloy (the ratio of Indium to Gallium). A higher indium content generally shifts the emission towards longer wavelengths (e.g., green, rather than blue). The side-looking package is achieved by mounting the semiconductor chip on its side within the leadframe cavity, so that its primary light-emitting surface faces outward through the side of the molded plastic lens, rather than upward.

13. Industry Trends & Developments

Kasuwar SMD LED na ci gaba da haɓakawa tare da yanayi da yawa bayyananne:

• Ƙara Inganci (lm/W): Ongoing material science and chip design improvements yield more light output per unit of electrical power, reducing energy consumption and thermal load.
• Miniaturization: Packages continue to shrink (e.g., from 0603 to 0402 to 0201 metric sizes) while maintaining or improving optical performance, enabling denser and more compact electronic designs.
• Improved Color Consistency & Binning: Advances in epitaxial growth and manufacturing control lead to tighter parameter distributions, reducing the need for extensive binning and improving yield.
• Higher Reliability & Lifetime: Uboreshaji katika vifaa vya ufungashaji (mfano, plastiki za joto la juu, kiambatisho cha kufa chenye nguvu) na teknolojia ya chipi huongeza maisha ya uendeshaji, na kufanya LED zifae kwa matumizi magumu zaidi ya magari, viwanda, na matibabu.
• Suluhisho Zilizounganishwa: Ukuaji katika LED zenya madereva vilivyojengwa ndani (IC za mkondo thabiti), vipengele vya ulinzi (ESD, mawimbi), au hata vikokotoo vidogo kwa matumizi ya RGB yanayoweza kuanzishwa (mfano, LED za aina ya WS2812).

Ingawa hii datasheet maalum inawakilisha bidhaa imara na ya kuaminika, vizazi vipya vingekuwa vinaonyesha mielekeo hii kwa viashiria bora vya utendaji na uwezekano wa umbo dogo zaidi.