SMD LED 23-21B Brilliant Orange Datasheet - Package 2.0x1.25x0.8mm - Voltage 1.75-2.35V - Power 60mW - English Technical Document

1. Product Overview

The 23-21B is a surface-mount device (SMD) LED designed for applications requiring a brilliant orange indicator or backlight source. It utilizes an AlGaInP (Aluminum Gallium Indium Phosphide) chip material to produce its characteristic orange color with a water-clear resin encapsulation. This component is significantly smaller than traditional lead-frame type LEDs, enabling higher packing density on printed circuit boards (PCBs), reduced equipment size, and lighter overall product weight, making it ideal for space-constrained and miniature applications.

Key advantages of this LED include its compatibility with standard automated pick-and-place assembly equipment and mainstream soldering processes such as infrared and vapor phase reflow. It is a Pb-free (lead-free) product, compliant with the RoHS (Restriction of Hazardous Substances) directive, EU REACH regulations, and halogen-free requirements (Br <900 ppm, Cl <900 ppm, Br+Cl < 1500 ppm). The device is supplied on 8mm tape wound on 7-inch diameter reels for efficient manufacturing handling.

2. Technical Specifications and Objective Interpretation

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 (VR): 5V. Exceeding this voltage in reverse bias can cause junction breakdown.
• Continuous Forward Current (IF): 25 mA. The maximum DC current for reliable long-term operation.
• Peak Forward Current (IFP): 50 mA. This pulsed current (1/10 duty cycle at 1 kHz) rating is for short-duration, non-continuous operation.
• Power Dissipation (Pd): 60 mW. The maximum power the package can dissipate at an ambient temperature (Ta) of 25°C. This value derates with increasing ambient temperature.
• Electrostatic Discharge (ESD) Human Body Model (HBM): 2000V. This indicates a moderate level of ESD robustness. Standard ESD handling precautions (e.g., grounded workstations, wrist straps) are still recommended during assembly.
• Operating Temperature (Topr): -40°C to +85°C. The ambient temperature range over which the device is specified to operate.
• Storage Temperature (Tstg): -40°C to +90°C.
• Soldering Temperature (Tsol): Reflow soldering: 260°C peak for a maximum of 10 seconds. Hand soldering: 350°C iron tip temperature for a maximum of 3 seconds per terminal.

2.2 Electro-Optical Characteristics

These parameters are measured at a standard test condition of Ta=25°C and IF=20mA, unless otherwise specified. They define the typical performance of the device.

• Luminous Intensity (Iv): 45.0 to 112.0 mcd (millicandela). The actual output falls into specific bins (P1, P2, Q1, Q2). A tolerance of ±11% applies.
• Viewing Angle (2θ1/2): 130 degrees (typical). This is the full angle at which the luminous intensity is half of the peak intensity (on-axis). It indicates a wide viewing pattern suitable for indicator applications.
• Peak Wavelength (λp): 611 nm (typical). The wavelength at which the spectral power distribution is maximum.
• Dominant Wavelength (λd): 600.5 to 612.5 nm. This is the single wavelength perceived by the human eye as the color of the light. It is binned into ranges D8 through D11 with a tolerance of ±1nm.
• Spectral Bandwidth (Δλ): 17 nm (typical). The width of the emitted spectrum at half the maximum intensity (FWHM). A narrower bandwidth indicates a more saturated, pure color.
• Forward Voltage (VF): 1.75 to 2.35 V at IF=20mA. This is binned into three ranges (0, 1, 2) with a tolerance of ±0.1V. Lower VF generally leads to higher efficiency and less heat generation.
• Reverse Current (IR): 10 μA (max) at VR=5V. This is a leakage current measurement parameter; 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. The 23-21B uses a three-dimensional binning system.

3.1 Luminous Intensity Binning (CAT)

Defines the minimum and maximum luminous intensity for each bin code at IF=20mA.

• P1: 45.0 - 57.0 mcd
• P2: 57.0 - 72.0 mcd
• Q1: 72.0 - 90.0 mcd
• Q2: 90.0 - 112.0 mcd

3.2 Dominant Wavelength Binning (HUE)

Defines the color (wavelength) range for each bin code.

• D8: 600.5 - 603.5 nm
• D9: 603.5 - 606.5 nm
• D10: 606.5 - 609.5 nm
• D11: 609.5 - 612.5 nm

3.3 Forward Voltage Binning (REF)

Groups LEDs by their forward voltage drop at IF=20mA, which is important for current-limiting resistor calculation and power supply design.

• 0: 1.75 - 1.95 V
• 1: 1.95 - 2.15 V
• 2: 2.15 - 2.35 V

4. Performance Curve Analysis

The datasheet provides several characteristic curves that illustrate device behavior under varying conditions.

4.1 Relative Luminous Intensity vs. Forward Current

This curve shows that luminous intensity increases with forward current, but the relationship is not perfectly linear, especially at higher currents. It highlights the importance of driving the LED at its specified test current (20mA) to achieve the rated luminous intensity.

4.2 Relative Luminous Intensity vs. Ambient Temperature

This graph demonstrates the thermal quenching effect common in LEDs: as the junction temperature rises (due to increased ambient temperature or self-heating), the luminous output decreases. The output is normalized to 100% at 25°C. Designers must account for this derating in applications with high ambient temperatures.

3.3 Forward Current Derating Curve

This is a critical design tool. It shows the maximum allowable continuous forward current as a function of ambient temperature. As ambient temperature increases, the maximum safe current must be reduced to prevent exceeding the device's maximum junction temperature and power dissipation rating. For example, at 85°C, the maximum continuous current is significantly lower than the 25mA rating at 25°C.

4.4 Forward Voltage vs. Forward Current

This IV (Current-Voltage) curve shows the exponential relationship typical of a diode. The forward voltage increases with current. The curve's slope in the operating region helps determine the dynamic resistance of the LED.

4.5 Radiation Pattern

A polar diagram illustrating the spatial distribution of light intensity. The 23-21B shows a typical lambertian or near-lambertian pattern, with intensity decreasing as the viewing angle moves away from the central axis (0°).

4.6 Spectral Distribution

A graph of relative intensity versus wavelength, centered around the peak wavelength of ~611 nm. It confirms the monochromatic nature of the AlGaInP chip with a defined spectral bandwidth.

5. Mechanical and Package Information

5.1 Package Dimensions

The LED has a compact SMD footprint. Key dimensions (in mm, tolerance ±0.1mm unless noted) include:
- Overall Length: 2.0 mm
- Overall Width: 1.25 mm
- Overall Height: 0.8 mm
- Cathode Identifier: A chamfer or marking on the package denotes the cathode (negative) terminal. Correct polarity orientation during placement is essential.

5.2 Recommended PCB Land Pattern

A suggested pad layout is provided to ensure reliable soldering and proper mechanical alignment. The pad design accommodates the component's terminals and allows for appropriate solder fillet formation. Following this recommendation helps prevent tombstoning and ensures good thermal and electrical connection.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Profile (Pb-free)

A specific temperature profile is recommended for lead-free solder:
- Preheat: 150-200°C for 60-120 seconds.
- Time Above Liquidus (217°C): 60-150 seconds.
- Peak Temperature: 260°C maximum, held for no more than 10 seconds.
- Heating Rate: Maximum 6°C/second up to 255°C, then 3°C/second maximum to peak.
- Cooling Rate: Controlled to minimize thermal stress.
Important: Reflow soldering should not be performed more than two times on the same device.

6.2 Hand Soldering

If manual repair is necessary, extreme care must be taken:
- Soldering iron tip temperature: < 350°C.
- Contact time per terminal: < 3 seconds.
- Soldering iron power: < 25W.
- A minimum 2-second interval should be left between soldering each terminal.
- A double-head soldering iron is suggested for removal to apply heat evenly to both terminals simultaneously and avoid mechanical stress.

6.3 Storage and Moisture Sensitivity

The LEDs are packaged in a moisture-resistant barrier bag with desiccant to prevent absorption of atmospheric moisture, which can cause \"popcorning\" (package cracking) during reflow.
- Do not open the bag until ready for use.
- After opening, unused parts should be stored at ≤30°C and ≤60% Relative Humidity (RH).
- The \"floor life\" after bag opening is 168 hours (7 days).
- If the floor life is exceeded or the desiccant indicator shows saturation, a bake-out at 60 ±5°C for 24 hours is required before reflow.

7. Packaging and Ordering Information

7.1 Reel and Tape Specifications

The device is supplied in embossed carrier tape:
- Tape Width: 8 mm.
- Reel Diameter: 7 inches (178 mm).
- Quantity per Reel: 2000 pieces.
- Reel dimensions (hub, flange) are provided for compatibility with automated feeders.

7.2 Label Explanation

The reel label contains critical information for traceability and correct application:
- CPN: Customer's Product Number (optional).
- P/N: Manufacturer's Part Number (23-21B/S2C-AP1Q2B/2A).
- QTY: Packing Quantity.
- CAT: Luminous Intensity Bin Code (e.g., Q2).
- HUE: Dominant Wavelength Bin Code (e.g., D10).
- REF: Forward Voltage Bin Code (e.g., 1).
- LOT No.: Manufacturing Lot Number for traceability.

8. Application Suggestions and Design Considerations

8.1 Typical Applications

• Backlighting: Dashboard indicators, switch illumination, keypads.
• Telecommunications: Status indicators and backlights in telephones, fax machines, and networking equipment.
• Consumer Electronics: Symbol and status indication in various portable and fixed devices.
• General Purpose Indication: Any application requiring a bright, reliable orange indicator.

8.2 Critical Design Considerations

1. Current Limiting: An external current-limiting resistor is absolutely mandatory. The LED's exponential V-I characteristic means a small increase in voltage can cause a large, destructive increase in current. The resistor value (R) is calculated using Ohm's Law: R = (Vsupply - VF) / IF, where VF should be the maximum value from the bin (e.g., 2.35V) to ensure safe operation under all conditions.
2. Thermal Management: Consider the derating curves. In high ambient temperature environments or if driven near maximum current, ensure adequate PCB copper area or other means to dissipate heat and keep the junction temperature within safe limits.
3. ESD Protection: While rated for 2000V HBM, incorporating transient voltage suppression (TVS) diodes or resistors on sensitive lines in ESD-prone environments (e.g., user-accessible indicators) is good practice.
4. Optical Design: The wide 130° viewing angle provides good off-axis visibility. For applications requiring a more focused beam, secondary optics (lenses) would be needed.

9. Technical Comparison and Differentiation

The 23-21B, based on AlGaInP technology, offers distinct advantages for orange/red color applications compared to other technologies like phosphor-converted white LEDs or older GaAsP devices.

• vs. Phosphor-Converted LEDs: AlGaInP provides higher luminous efficacy and more saturated color purity in the orange-red spectrum without the efficiency losses associated with phosphor conversion.
• vs. Older GaAsP LEDs: AlGaInP technology offers significantly higher brightness and better temperature stability.
• vs. Larger Leaded LEDs: The SMD package enables automated assembly, reduces board space, and improves reliability by eliminating bent leads and manual insertion errors.
• Key Differentiator: The combination of a specific brilliant orange color from a direct-emitting semiconductor, compact SMD package, and compliance with modern environmental regulations (RoHS, Halogen-Free) makes it suitable for contemporary electronic designs.

10. Frequently Asked Questions (Based on Technical Parameters)

Q1: What resistor value should I use with a 5V supply?
A1: Using the worst-case maximum VF of 2.35V and desired IF of 20mA: R = (5V - 2.35V) / 0.020A = 132.5 Ohms. The nearest standard higher value (e.g., 150 Ohms) would be a safe choice, resulting in IF ≈ 17.7mA.

Q2: Can I drive this LED at 30mA for more brightness?
A2: The Absolute Maximum Rating for continuous forward current is 25mA. Operating at 30mA exceeds this rating, which may reduce reliability and lifetime, cause excessive heat, and potentially lead to immediate failure. Always operate within the specified limits.

Q3: The luminous intensity bin is Q2 (90-112 mcd). What output can I expect in my design?
A3: You can conservatively design for the minimum value of 90 mcd. The actual device you receive will be between 90 and 112 mcd. The ±11% tolerance applies to the bin limits, so a specific device labeled Q2 could theoretically be as low as ~80 mcd or as high as ~124 mcd, though it will be within the Q2 range.

Q4: How do I interpret the soldering profile graph?
A4: The graph shows temperature (Y-axis) vs. time (X-axis). Your reflow oven must be programmed so that the temperature measured at the LED leads follows this trajectory: a gradual preheat, a controlled ramp-up, a specific time above the solder melting point (217°C), a controlled peak temperature (≤260°C), and a controlled cool-down. Deviating significantly, especially exceeding time-at-temperature limits, can damage the LED.

11. Practical Design and Usage Case

Scenario: Designing a status indicator panel with multiple orange LEDs.

1. Binning Selection: For uniform appearance, specify tight bins for both Dominant Wavelength (HUE, e.g., D10 only) and Luminous Intensity (CAT, e.g., Q1 only). This ensures all indicators have nearly identical color and brightness.
2. Circuit Design: Using a 3.3V microcontroller supply. Assuming VF bin \"1\" (max 2.15V) and targeting 15mA for lower power consumption: R = (3.3V - 2.15V) / 0.015A = 76.7 Ohms. Use a 75 Ohm resistor. Power in resistor: (1.15V^2)/75Ω ≈ 18mW. Use a 1/10W or larger resistor.
3. PCB Layout: Place the LED according to the recommended land pattern. Include a small copper pour connected to the cathode pad to aid in heat dissipation, especially if multiple LEDs are placed close together.
4. Assembly: Keep reels in sealed bags until loaded into the pick-and-place machine. Follow the reflow profile precisely. After assembly, avoid bending the PCB near the LEDs.

12. Operating Principle Introduction

The 23-21B LED operates on the principle of electroluminescence in a semiconductor p-n junction. The active region is composed of AlGaInP (Aluminum Gallium Indium Phosphide) layers grown epitaxially on a substrate. When a forward voltage exceeding the junction's built-in potential is applied, electrons from the n-type region and holes from the p-type region are injected into the active region. Here, they recombine radiatively, releasing energy in the form of photons (light). The specific composition of the AlGaInP alloy determines the bandgap energy, which directly dictates the wavelength (color) of the emitted light—in this case, brilliant orange (~611 nm). The water-clear epoxy resin encapsulates the chip, provides mechanical protection, and acts as a primary lens shaping the light output pattern.

13. Technology Trends and Context

SMD LEDs like the 23-21B represent the mainstream packaging technology for indicator and low-power lighting applications, having largely replaced through-hole LEDs. The trend in this sector continues towards:
- Miniaturization: Even smaller package footprints (e.g., 0402, 0201 metric) for ultra-high-density boards.
- Increased Efficiency: Ongoing improvements in epitaxial growth and chip design yield higher luminous efficacy (more light output per electrical watt).
- Enhanced Reliability: Improved packaging materials and processes lead to longer operational lifetimes and better performance under harsh environmental conditions (temperature, humidity).
- Integration: Growth of multi-chip packages (RGB, multi-color) and LEDs with integrated controllers (ICs) for smart lighting applications.
- Broadened Spectrum: Development of semiconductor materials to efficiently produce colors across the entire visible spectrum and into ultraviolet (UV) and infrared (IR). While AlGaInP dominates the red-orange-amber-yellow range, other materials like InGaN are used for blue, green, and white LEDs.

The 23-21B fits into this landscape as a reliable, standardized component offering a balance of performance, size, and cost for its target color and application range.