SMD LED 19-217 Datasheet - Reddish Orange - 120° Viewing Angle - 5mA Forward Current - English Technical Document

1. Product Overview

The 19-217 is a surface-mount device (SMD) LED designed for modern, compact electronic assemblies. It utilizes an AlGaInP (Aluminum Gallium Indium Phosphide) chip to produce a reddish-orange light output. Its primary advantage lies in its significantly reduced footprint compared to traditional lead-frame LEDs, enabling higher packing density on printed circuit boards (PCBs), reduced storage requirements, and ultimately contributing to the miniaturization of end equipment. The component is lightweight, making it suitable for applications where space and weight are critical constraints.

1.1 Core Advantages

• Miniaturization: The SMD package allows for smaller board designs.
• Automation Compatibility: Supplied on 8mm tape on 7-inch reels, it is fully compatible with high-speed automatic pick-and-place equipment.
• Process Compatibility: Suitable for both infrared and vapor phase reflow soldering processes.
• Environmental Compliance: The product is Pb-free, compliant with RoHS, EU REACH, and halogen-free standards (Br <900 ppm, Cl <900 ppm, Br+Cl < 1500 ppm).

1.2 Target Applications

This LED is versatile and finds use in various illumination and indication roles, including:

• Backlighting for instrument panels, switches, and symbols.
• Status indicators and keypad backlighting in telecommunication devices like phones and fax machines.
• General-purpose indicator lights.

2. Technical Parameter Deep Dive

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. Operation under these conditions is not guaranteed.

• Reverse Voltage (V_R): 5 V
• Continuous Forward Current (I_F): 25 mA
• Peak Forward Current (I_FP): 60 mA (at 1/10 duty cycle, 1 kHz)
• Power Dissipation (P_d): 60 mW
• Electrostatic Discharge (ESD) Human Body Model (HBM): 2000 V
• Operating Temperature (T_opr): -40°C to +85°C
• Storage Temperature (T_stg): -40°C to +90°C
• Soldering Temperature (T_sol): Reflow: 260°C for 10 sec max; Hand: 350°C for 3 sec max.

2.2 Electro-Optical Characteristics

Measured at an ambient temperature (T_a) of 25°C and a standard test current (I_F) of 5 mA, unless otherwise specified.

• Luminous Intensity (I_v): 14.5 mcd (Min), 36.0 mcd (Max). A ±11% tolerance applies.
• Viewing Angle (2θ_1/2): 120 degrees (Typical). This wide angle ensures good visibility from various perspectives.
• Peak Wavelength (λ_p): 621 nm (Typical).
• Dominant Wavelength (λ_d): 605.5 nm (Min), 625.5 nm (Max). A ±1 nm tolerance applies. This parameter defines the perceived color.
• Spectral Bandwidth (Δλ): 18 nm (Typical). This indicates the spectral purity of the emitted light.
• Forward Voltage (V_F): 1.7 V (Min), 2.2 V (Max) at I_F=5mA. A ±0.05V tolerance applies. This is critical for current-limiting resistor calculation.
• Reverse Current (I_R): 10 μA (Max) at V_R=5V. The device is not designed for operation in reverse bias.

3. Binning System Explanation

To ensure color and brightness consistency in production, LEDs are sorted into bins based on key parameters.

3.1 Luminous Intensity Binning

Binned at I_F = 5 mA.

• L2: 14.5 – 18.0 mcd
• M1: 18.0 – 22.5 mcd
• M2: 22.5 – 28.5 mcd
• N1: 28.5 – 36.0 mcd

3.2 Dominant Wavelength Binning

Binned at I_F = 5 mA. This directly correlates to the shade of reddish-orange.

• E1: 605.5 – 609.5 nm
• E2: 609.5 – 613.5 nm
• E3: 613.5 – 617.5 nm
• E4: 617.5 – 621.5 nm
• E5: 621.5 – 625.5 nm

3.3 Forward Voltage Binning

Binned at I_F = 5 mA. Important for designing uniform current drive circuits across multiple LEDs.

• 19: 1.7 – 1.8 V
• 20: 1.8 – 1.9 V
• 21: 1.9 – 2.0 V
• 22: 2.0 – 2.1 V
• 23: 2.1 – 2.2 V

4. Performance Curve Analysis

The datasheet provides several characteristic curves that are essential for understanding the LED's behavior under different operating conditions.

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

This non-linear relationship shows that a small increase in voltage beyond the typical V_F can cause a large, potentially damaging increase in current. This underscores the absolute necessity of using a current-limiting resistor or constant-current driver in series with the LED.

4.2 Relative Luminous Intensity vs. Forward Current

The light output increases with forward current but not linearly. Operating above the recommended continuous current (25mA) may increase brightness but will reduce lifetime and reliability due to increased junction temperature.

4.3 Relative Luminous Intensity vs. Ambient Temperature

Luminous intensity decreases as the ambient temperature rises. This thermal derating is a critical consideration for applications operating in high-temperature environments. The curve shows performance from -40°C to +100°C.

4.4 Forward Current Derating Curve

This curve defines the maximum allowable continuous forward current as a function of ambient temperature. To prevent overheating, the maximum current must be reduced when operating above a certain temperature (typically 25°C).

4.5 Spectral Distribution

The graph shows the relative intensity of light emitted across different wavelengths, centered around the peak wavelength of 621 nm. The shape and width (18 nm) of this curve determine the color purity.

4.6 Radiation Pattern

A polar diagram illustrating the angular distribution of light intensity, confirming the 120-degree viewing angle where intensity falls to half its maximum value.

5. Mechanical and Package Information

The LED comes in a standard SMD package. The exact dimensions (length, width, height) and pad layout are defined in the package drawing within the datasheet. The drawing includes critical dimensions such as the lead spacing and recommended PCB land pattern to ensure proper soldering and mechanical stability. The component features a clear resin lens. Polarity is indicated by a marking on the package or by an asymmetric pad design (typically the cathode pad may be marked or have a different shape). Designers must consult the specific dimension drawing for accurate footprint creation.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Profile (Pb-free)

A critical process for reliable assembly.

• Pre-heating: 150–200°C for 60–120 seconds.
• Time Above Liquidus (217°C): 60–150 seconds.
• Peak Temperature: 260°C maximum.
• Time at Peak: 10 seconds maximum.
• Heating Rate: Maximum 6°C/second.
• Cooling Rate: Maximum 3°C/second.

Important: Reflow soldering should not be performed more than two times on the same LED.

6.2 Hand Soldering

If manual soldering is unavoidable:

• Use a soldering iron with a tip temperature < 350°C.
• Limit contact time to 3 seconds per terminal.
• Use an iron with a power rating of 25W or less.
• Allow a minimum 2-second interval between soldering each terminal to prevent thermal shock.

6.3 Storage and Moisture Sensitivity

The LEDs are packaged in a moisture-resistant bag with desiccant.

• Do not open the bag until ready for use.
• After opening, unused LEDs should be stored at ≤30°C and ≤60% relative humidity.
• The "floor life" after opening is 168 hours (7 days).
• If the floor life is exceeded or the desiccant indicates moisture absorption, a baking treatment is required: 60 ±5°C for 24 hours before use.

7. Packaging and Ordering Information

The standard packaging is 3000 pieces per reel. The reel, carrier tape, and cover tape dimensions are specified to ensure compatibility with automated equipment. The label on the reel provides key information for traceability and correct application: Product Number (P/N), quantity (QTY), and the specific bin codes for Luminous Intensity (CAT), Dominant Wavelength (HUE), and Forward Voltage (REF).

8. Application Design Considerations

8.1 Current Limiting is Mandatory

An external current-limiting resistor must always be used in series with the LED. The resistor value (R) can be calculated using Ohm's Law: R = (V_supply - V_F) / I_F, where V_F is the forward voltage of the LED at the desired current I_F. Always use the maximum V_F from the datasheet for a conservative design to prevent overcurrent.

8.2 Thermal Management

While the package is small, power dissipation (up to 60mW) generates heat. Ensure adequate PCB copper area (thermal relief pads) around the LED solder pads to help dissipate heat, especially when operating at high currents or in warm environments. Adhere to the forward current derating curve.

8.3 ESD Protection

Although rated for 2000V HBM, standard ESD handling precautions should be observed during assembly and handling to prevent latent damage.

9. Technical Comparison and Differentiation

The 19-217 LED, based on AlGaInP technology, offers distinct advantages for reddish-orange applications compared to other technologies like AllnGaP or filtered LEDs. AlGaInP typically provides higher luminous efficiency and better color stability over temperature and current variations for colors in the red to amber spectrum. Its 120-degree viewing angle is wider than many "top-view" LEDs, making it suitable for applications requiring broad visibility. The SMD format provides a lower profile and better suitability for automated assembly than through-hole counterparts.

10. Frequently Asked Questions (FAQ)

10.1 Why does my LED need a resistor?

LEDs are current-driven devices. Their I-V characteristic is exponential, meaning a tiny increase in voltage causes a large current increase, which can instantly destroy the LED. A resistor limits the current to a safe, specified value.

10.2 Can I drive this LED with a 5V supply?

Yes, but you must use a series resistor. For example, to achieve I_F=5mA with a V_supply=5V and a typical V_F=2.0V, the resistor value would be R = (5V - 2.0V) / 0.005A = 600 Ohms. Use a standard value like 620 Ohms.

10.3 What happens if I exceed the maximum soldering temperature or time?

Excessive heat can damage the internal semiconductor die, the wire bonds, or the epoxy lens, leading to immediate failure or reduced long-term reliability (decreased light output, color shift). Always follow the recommended profile.

10.4 How do I interpret the bin codes on the label?

The bin codes (e.g., CAT: N1, HUE: E4, REF: 21) tell you the specific performance group of the LEDs on that reel. "N1" means luminous intensity is between 28.5-36.0 mcd, "E4" means dominant wavelength is 617.5-621.5 nm, and "21" means forward voltage is 1.9-2.0V. This allows for consistent performance in your product.

11. Design and Usage Case Study

Scenario: Designing a status indicator panel for an industrial controller. The panel requires multiple reddish-orange indicators that must be uniformly bright and have the same color shade, visible from a wide angle by an operator.

Implementation:

1. Component Selection: The 19-217 LED is chosen for its SMD format (eases automated assembly), wide 120° viewing angle, and available binning for consistency.
2. Circuit Design: A 5V rail is available. Targeting I_F = 5mA for long life and moderate brightness. Using the maximum V_F of 2.2V for a conservative design: R = (5V - 2.2V) / 0.005A = 560 Ohms. A 560Ω, 1/8W resistor is placed in series with each LED.
3. PCB Layout: LEDs are placed with adequate spacing. The PCB footprint follows the recommended land pattern from the datasheet. Additional copper pour is connected to the cathode pad for slight thermal improvement.
4. Procurement: LEDs are ordered specifying tight binning requirements (e.g., CAT: M2 or N1, HUE: E3 or E4) to ensure visual uniformity across all indicators on the panel.
5. Assembly: Components are assembled using a standard Pb-free reflow profile, strictly adhering to the time and temperature limits.

This approach results in a reliable, consistent, and professional-looking indicator panel.

12. Operating Principle

Light is produced through a process called electroluminescence. When a forward voltage exceeding the diode's built-in potential is applied, electrons from the n-type semiconductor and holes from the p-type semiconductor are injected into the active region (the quantum well in the AlGaInP layer). When these electrons and holes recombine, energy is released in the form of photons (light). The specific composition of the AlGaInP alloy determines the bandgap energy, which in turn dictates the wavelength (color) of the emitted light—in this case, reddish-orange (~621 nm). The clear epoxy resin package acts as a lens, shaping the light output into the desired radiation pattern.

13. Technology Trends

The general trend in indicator LEDs like the 19-217 is towards ever-higher efficiency (more light output per unit of electrical input), which reduces power consumption and heat generation. There is also a continuous drive for miniaturization, leading to smaller package sizes (e.g., 0402, 0201 metric) while maintaining or improving optical performance. Advances in phosphor and semiconductor materials continue to improve color rendering, stability, and lifetime. Furthermore, integration of control electronics (like constant-current drivers) directly into LED packages is becoming more common for simplified design. The underlying AlGaInP technology remains a high-performance standard for red, orange, and amber colors due to its efficiency and stability.