SMD LED LTW-C190DA5 Datasheet - White InGaN - 5mA Forward Current - 45-180mcd Luminous Intensity - English Technical Document

1. Product Overview

This document provides the complete technical specifications for a surface-mount device (SMD) Light Emitting Diode (LED) utilizing an Ultra Bright Indium Gallium Nitride (InGaN) white chip. The component is designed for automated assembly processes and is compliant with RoHS and green product standards, making it suitable for environmentally conscious electronic designs.

The LED is supplied in industry-standard 8mm tape on 7-inch diameter reels, facilitating high-volume, automated pick-and-place manufacturing. Its design is compatible with infrared (IR) reflow soldering processes, which is the standard for modern surface-mount technology (SMT) assembly lines. The device is also noted as being I.C. compatible, indicating its electrical characteristics are suitable for direct interfacing with integrated circuit outputs without requiring additional driver circuitry in many applications.

2. Absolute Maximum Ratings

The absolute maximum ratings define the stress limits beyond which permanent damage to the device may occur. These ratings are specified at an ambient temperature (Ta) of 25\u00b0C and must not be exceeded under any operating conditions.

• Power Dissipation (Pd): 72 mW. This is the maximum total power the LED package can dissipate as heat.
• Peak Forward Current (I_F(PEAK)): 100 mA. This current is permissible only under pulsed conditions with a 1/10 duty cycle and a 0.1ms pulse width. It should not be used for DC operation.
• DC Forward Current (I_F): 20 mA. This is the maximum continuous forward current recommended for reliable long-term operation.
• Reverse Voltage (V_R): 5 V. Applying a reverse voltage exceeding this limit can cause immediate and catastrophic failure. The datasheet explicitly notes that reverse voltage cannot be used for continued operation.
• Operating Temperature Range (T_opr): -30\u00b0C to +85\u00b0C. The device is guaranteed to function within this ambient temperature range.
• Storage Temperature Range (T_stg): -55\u00b0C to +105\u00b0C.
• Infrared Soldering Condition: The package can withstand a peak temperature of 260\u00b0C for a maximum of 10 seconds during reflow soldering.

3. Electrical & Optical Characteristics

The typical electrical and optical characteristics are measured at an ambient temperature of 25\u00b0C and a forward current (I_F) of 5 mA, unless otherwise stated. This forms the baseline for device performance.

• Luminous Intensity (I_V): 45.0 mcd (Min), 180.0 mcd (Max). The intensity is measured using a sensor and filter combination that approximates the CIE photopic eye-response curve. The actual value for a specific unit falls within a binning range (see Section 4).
• Viewing Angle (2\u03b8_1/2): 130 degrees (Typical). This wide viewing angle indicates a Lambertian or near-Lambertian emission pattern, suitable for applications requiring broad area illumination.
• Chromaticity Coordinates (x, y): x=0.203, y=0.319 (Typical). These coordinates on the CIE 1931 chromaticity diagram define the white point of the LED. A tolerance of \u00b10.01 applies to these values, and specific units are binned accordingly.
• Forward Voltage (V_F): 2.55 V (Min), 3.15 V (Max) at I_F=5mA. The typical value is implied to be around the center of this range. V_F is also subject to binning.
• Reverse Current (I_R): 10 \u00b5A (Max) at V_R=5V.

Important Notes:

• ESD Caution: The LED is sensitive to Electrostatic Discharge (ESD) and electrical surges. Proper ESD handling procedures are mandatory, including the use of grounded wrist straps, anti-static gloves, and ensuring all equipment is properly grounded.
• Measurement Equipment: The chromaticity coordinates and luminous intensity values are verified using a CAS140B tester.

4. Binning System Explanation

To ensure consistency in mass production, LEDs are sorted into performance bins. The LTW-C190DA5 uses a three-dimensional binning system for Forward Voltage (V_F), Luminous Intensity (I_V), and Hue (Chromaticity coordinates x, y).

4.1 Forward Voltage (V_F) Binning

At a test current of 5mA, units are classified into three bins:
- Bin A: V_F = 2.55V to 2.75V
- Bin B: V_F = 2.75V to 2.95V
- Bin C: V_F = 2.95V to 3.15V
A tolerance of \u00b10.1V is applied to each bin limit.

4.2 Luminous Intensity (I_V) Binning

At a test current of 5mA, units are classified into three bins:
- Bin P: I_V = 45.0 mcd to 71.0 mcd
- Bin Q: I_V = 71.0 mcd to 112.0 mcd
- Bin R: I_V = 112.0 mcd to 180.0 mcd
A tolerance of \u00b115% is applied to each bin limit.

4.3 Hue (Chromaticity) Binning

This is the most complex binning parameter, defining the color point of the white light on the CIE 1931 diagram. Eight bins (A1 through A8) are defined, each representing a small quadrilateral area on the (x, y) coordinate plane. The provided table and diagram on page 5 detail the exact corner coordinates for each bin. A tolerance of \u00b10.01 is applied to the (x, y) values within each bin. This system allows designers to select LEDs with very tight color consistency for applications where uniform white appearance is critical.

5. Package & Mechanical Information

The LED is provided in a standard SMD package. The specific package dimensions are detailed in the datasheet drawings. Key mechanical notes include:

• All primary dimensions are provided in millimeters, with an accompanying tolerance of \u00b10.10 mm (0.004\") unless otherwise specified.
• The lens color is specified as \"Green,\" which typically refers to the color of the encapsulating resin, not the emitted light color (which is white).
• Recommended solder pad dimensions are provided to ensure a reliable solder joint and proper alignment during reflow.

6. Soldering, Assembly & Storage Guidelines

6.1 Soldering Process

The component is fully compatible with infrared (IR) reflow soldering. The suggested profile must adhere to the absolute maximum rating of 260\u00b0C for 10 seconds. A typical recommended condition includes a pre-heat stage at 150-200\u00b0C for a maximum of 120 seconds, followed by a peak temperature not exceeding 260\u00b0C. The time above liquidus and the cooling rate should be controlled according to standard JEDEC guidelines for SMT assembly. Hand soldering with an iron is possible but strictly limited: a maximum iron tip temperature of 300\u00b0C for no more than 3 seconds, and only one soldering attempt is permitted.

6.2 Storage Conditions

Proper storage is crucial for maintaining solderability:
- Sealed Package: Store at \u2264 30\u00b0C and \u2264 90% Relative Humidity (RH). The shelf life is one year when the moisture-proof bag with desiccant is intact.
- Opened Package: If the original packaging is opened, the storage ambient must not exceed 30\u00b0C and 60% RH. Components should be used within one week. For longer storage outside the original bag, they must be kept in a sealed container with desiccant or in a nitrogen desiccator. Components stored for more than one week outside the original packaging require a baking pre-treatment (approximately 60\u00b0C for at least 20 hours) before soldering to remove absorbed moisture and prevent \"popcorning\" damage during reflow.

6.3 Cleaning

If cleaning after soldering is necessary, only specified solvents should be used. Immersing the LED in ethyl alcohol or isopropyl alcohol at normal temperature for less than one minute is acceptable. The use of unspecified chemical liquids can damage the LED package.

7. Packaging & Reel Specifications

The product is supplied for automated assembly:
- Packaged in 8mm wide embossed carrier tape.
- Reeled onto standard 7-inch (178mm) diameter reels.
- Each full reel contains 4000 pieces.
- Minimum order quantity for remnants is 500 pieces.
- The tape and reel specifications comply with ANSI/EIA 481-1-A-1994.
- Empty pockets in the tape are sealed with a cover tape.
- The maximum allowed number of consecutive missing components (\"missing lamps\") on a reel is two.

8. Application Notes & Design Considerations

Intended Use: This LED is designed for standard electronic equipment applications, including office equipment, communication devices, and household appliances.

Critical Applications: The datasheet contains a crucial disclaimer. It states that consultation is required before using this LED in applications where exceptional reliability is needed, particularly where failure could risk life or health. This includes, but is not limited to, aviation, transportation, traffic control, medical/life-support systems, and safety devices. For such applications, components with appropriate reliability qualifications must be sourced.

Circuit Design: Due to the diode nature of LEDs, a current-limiting resistor or constant-current driver is almost always required in series with the LED when connecting to a voltage source. The value of the series resistor (R_s) can be calculated using Ohm's Law: R_s = (V_supply - V_F) / I_F. Designers should use the maximum V_F from the bin or datasheet to ensure sufficient current under all conditions. The wide V_F range (2.55V-3.15V) highlights the importance of this calculation or the use of active constant-current drivers for consistent brightness.

Thermal Management: While not a high-power LED, adhering to the maximum power dissipation (72mW) and operating temperature range is important for longevity. Excessive current or poor PCB thermal design leading to high junction temperatures will accelerate lumen depreciation and reduce operational life.

9. Technical Comparison & Key Features

The LTW-C190DA5 represents a standard-brightness white SMD LED for general indication and backlighting purposes. Its key differentiators and features include:

• InGaN Technology: The use of an Indium Gallium Nitride chip is standard for modern white and blue LEDs, offering good efficiency and reliability.
• RoHS/Green Compliance: Essential for most global markets today.
• Comprehensive Binning: The three-parameter binning (V_F, I_V, Hue) allows for precise selection for applications requiring color or brightness uniformity across multiple LEDs.
• SMT Compatibility: The 8mm tape and reel packaging and compatibility with IR reflow are mandatory for cost-effective, high-volume manufacturing.
• Wide Viewing Angle: The 130-degree viewing angle makes it suitable for applications where the LED needs to be visible from a wide range of positions, not just directly on-axis.

10. Frequently Asked Questions (FAQ)

Q1: What is the typical forward voltage for driving this LED?
A1: The typical V_F is around 2.85V at 5mA, but it can vary from 2.55V to 3.15V. Always design for the maximum V_F in your chosen bin to ensure the desired current is achieved.

Q2: Can I drive this LED with 20mA continuously?
A2: Yes, 20mA is the maximum recommended DC forward current. Operating at this maximum will produce the highest light output but may reduce long-term lifespan compared to lower currents. Always consider thermal management.

Q3: How do I interpret the Hue Binning diagram (Page 5)?
A3: The diagram plots the eight bins (A1-A8) on the CIE 1931 chromaticity chart. Each bin is a small quadrilateral. The (x, y) coordinates in the table define the corners of these quadrilaterals. You select a bin code to guarantee the color point of the LED falls within that specific region on the chart.

Q4: My assembly process uses a reflow profile with a peak of 250\u00b0C. Is this acceptable?
A4: Yes, a peak of 250\u00b0C is within the specified limit of 260\u00b0C max. Ensure the total time above the solder liquidus temperature and the ramp rates are controlled according to standard SMT guidelines.

Q5: Why is ESD protection so important for LEDs?
A5: The semiconductor junction in an LED is very sensitive to high-voltage electrostatic discharges, which can instantly degrade or destroy the device. ESD damage may not be immediately visible but can cause premature failure or altered performance.