Top View LED 45-21 Series Brilliant Yellow - 3.0x2.0x1.1mm - 2.25V Typ - 40mW - English Technical Data Sheet

1. Product Overview

This document details the specifications for a top-view, surface-mount LED component. The device is characterized by its brilliant yellow emission, achieved through an AlGaInP chip material encapsulated in a water-clear resin. The primary design advantages include a wide viewing angle and optimized light coupling via an internal reflector, making it particularly suitable for light pipe applications. Its low current requirement also positions it as an ideal choice for power-sensitive applications such as portable equipment.

The product is designed with reliability and compliance in mind. It features a white SMT package with an individual 2-pin lead frame. It is compliant with RoHS, EU REACH, and halogen-free standards (Br <900 ppm, Cl <900 ppm, Br+Cl < 1500 ppm). Furthermore, it is qualified according to the AEC-Q101 standard, making it suitable for demanding environments such as interior automotive lighting (e.g., dashboard backlighting).

2. Technical Parameter Deep-Dive

2.1 Absolute Maximum Ratings

The device must not be operated beyond these limits to prevent permanent damage.

• Reverse Voltage (V_R): 5 V
• Forward Current (I_F): 50 mA (Continuous)
• Peak Forward Current (I_FP): 100 mA (Duty 1/10 @1kHz)
• Power Dissipation (P_d): 120 mW
• Electrostatic Discharge (ESD) 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; Hand: 350°C for 3 sec.

2.2 Electro-Optical Characteristics (T_a=25°C)

Typical performance parameters measured under standard conditions.

• Luminous Intensity (I_v): 450 to 900 mcd (at I_F=20mA)
• Viewing Angle (2θ_1/2): 120 degrees (Typical)
• Peak Wavelength (λ_p): 591 nm (Typical)
• Dominant Wavelength (λ_d): 585.5 to 594.5 nm
• Spectrum Radiation Bandwidth (Δλ): 15 nm (Typical)
• Forward Voltage (V_F): 1.95 to 2.55 V (at I_F=20mA)
• Reverse Current (I_R): 10 μA Max (at V_R=5V)

Note: Tolerances are ±11% for luminous intensity, ±1nm for dominant wavelength, and ±0.1V for forward voltage.

3. Binning System Explanation

The device is sorted into bins based on key performance parameters to ensure consistency in application design.

3.1 Luminous Intensity Binning

• U1: 450 - 565 mcd
• U2: 565 - 715 mcd
• V1: 715 - 900 mcd

3.2 Dominant Wavelength Binning (Group A)

• D3: 585.5 - 588.5 nm
• D4: 588.5 - 591.5 nm
• D5: 591.5 - 594.5 nm

3.3 Forward Voltage Binning (Group C)

• 1: 1.95 - 2.15 V
• 2: 2.15 - 2.35 V
• 3: 2.35 - 2.55 V

4. Performance Curve Analysis

The typical electro-optical characteristic curves (referenced in the datasheet) illustrate the relationship between forward current and luminous intensity, forward voltage, and the impact of ambient temperature on performance. These curves are essential for designers to predict behavior under non-standard conditions, such as higher operating temperatures or varying drive currents. Analyzing these graphs helps in selecting appropriate current-limiting resistors and understanding potential brightness variations over the device's operating range.

5. Mechanical and Package Information

5.1 Package Outline Dimensions

The device has a compact SMT footprint. Key dimensions (in mm, tolerance ±0.1mm unless specified) are approximately 3.0mm in length, 2.0mm in width, and 1.1mm in height. A recommended soldering pad layout is provided to ensure proper mechanical and thermal connection during assembly.

5.2 Polarity Identification

The anode (+) is clearly marked on the top of the package. Correct polarity orientation is crucial during placement to ensure proper circuit operation.

6. Soldering and Assembly Guidelines

6.1 Soldering Methods

The primary recommended assembly method is infrared (IR) reflow soldering. A specific Pb-free reflow temperature profile is suggested, with a peak temperature of 260°C for a maximum of 10 seconds. Reflow soldering should not be performed more than two times. Hand soldering is permissible but must be done carefully at a tip temperature below 350°C for no more than 3 seconds per terminal, using a soldering iron with a capacity of 25W or less.

6.2 Storage and Handling Precautions

• ESD Sensitivity: The device is sensitive to electrostatic discharge. Proper ESD handling procedures must be followed.
• Moisture Sensitivity: The LEDs are packaged in a moisture-resistant bag with desiccant.
  • Do not open the bag until ready for use.
  • Before opening: Store at ≤30°C / ≤70% RH for up to one year.
  • After opening: Use within 3 days under conditions of ≤30°C / ≤60% RH. Unused parts must be resealed in a dry package.
  • If the desiccant indicator changes color or storage time is exceeded, a one-time bake at 60±5°C for 24 hours is required before use.

6.3 Critical Usage Notes

• Current Protection: An external current-limiting resistor is mandatory. The LED's exponential V-I characteristic means a small voltage increase can cause a large, destructive current surge.
• Stress Avoidance: Avoid applying mechanical stress to the LED body during heating (soldering) and do not warp the PCB after assembly.
• Repair: Repair after soldering is not recommended. If unavoidable, a dual-head soldering iron must be used to simultaneously heat both terminals to prevent damage.

7. Packaging and Ordering Information

7.1 Packaging Specifications

The components are supplied on embossed carrier tape, which is then wound onto reels. The standard reel contains 2000 pieces. Detailed dimensions for the carrier tape pockets and the reel are provided to facilitate automated pick-and-place machine setup.

7.2 Label Explanation

The reel label contains several codes for traceability and specification:

• P/N: Product Number (e.g., 45-21/YSC-AU1V1C/2T-AFM)
• LOT No: Manufacturing Lot Number
• QTY: Packing Quantity
• CAT: Luminous Intensity Bin Code (e.g., V1)
• HUE: Dominant Wavelength Bin Code (e.g., D4)
• REF: Forward Voltage Bin Code (e.g., 2)

8. Application Suggestions

8.1 Typical Application Scenarios

• Telecommunication Equipment: Status indicators and backlighting for phones and fax machines.
• Consumer Electronics: Flat backlighting for LCDs, switches, and symbols.
• General Illumination: Light pipe applications for even light distribution, ideal for panel indicators.
• Automotive Interiors: Dashboard backlighting and other interior lighting functions (qualified to AEC-Q101).

8.2 Design Considerations

• Drive Circuit: Always implement a series resistor to set the forward current. Calculate the resistor value based on the supply voltage (V_CC), the LED's forward voltage (V_F from the appropriate bin), and the desired current (I_F, not to exceed 50mA continuous).
• Thermal Management: While power dissipation is low, ensure adequate PCB copper area or thermal relief if operating at high ambient temperatures or near the maximum current.
• Optical Design: The 120-degree viewing angle and clear lens make this LED excellent for applications requiring wide-angle visibility or coupling into light guides. Consider the angular intensity distribution when designing light pipes or diffusers.

9. Technical Comparison and Differentiation

Compared to standard LEDs, this device offers several key advantages for specific applications. The wide 120-degree viewing angle is superior to many narrow-angle LEDs, providing more uniform illumination in panel applications without secondary optics. The AEC-Q101 qualification is a critical differentiator for automotive and other high-reliability markets, indicating rigorous testing for thermal shock, humidity resistance, and long-term stability. The combination of AlGaInP material for yellow/orange/red colors typically offers higher luminous efficiency and better temperature stability than older technologies like GaAsP. The halogen-free and Pb-free compliance ensures adherence to modern environmental regulations.

10. Frequently Asked Questions (Based on Technical Parameters)

10.1 What resistor value should I use with a 5V supply?

Using the typical forward voltage of 2.25V and a target current of 20mA, the calculation is: R = (V_CC - V_F) / I_F = (5V - 2.25V) / 0.02A = 137.5 Ω. A standard 150 Ω resistor would result in a slightly lower current, around 18.3mA, which is safe and within specifications. Always use the maximum V_F from the datasheet (2.55V) for a worst-case design to ensure the current never exceeds the desired limit.

10.2 Can I drive this LED with a PWM signal for dimming?

Yes, pulse-width modulation (PWM) is an effective method for dimming LEDs. Ensure the peak current in each pulse does not exceed the absolute maximum rating of 50mA (continuous) or 100mA (pulsed). The frequency should be high enough (typically >100Hz) to avoid visible flicker.

10.3 Why is the storage and baking procedure so important?

SMD packages can absorb moisture from the atmosphere. During the high-temperature reflow soldering process, this trapped moisture can rapidly expand, causing internal delamination or \"popcorning,\" which cracks the package and destroys the device. The baking process gently drives out this absorbed moisture before the component undergoes reflow.

11. Practical Design Case Study

Scenario: Designing a cluster of status indicators for a industrial control panel. The indicators need to be visible from a wide angle, reliable, and driven directly from a microcontroller's 3.3V GPIO pins.
Solution: This LED is an excellent fit. The 120-degree viewing angle ensures visibility from various operator positions. The AEC-Q101-level reliability is beneficial for industrial environments. For the circuit, using a 3.3V supply and assuming a V_F of 2.25V at 20mA, a series resistor of (3.3V - 2.25V)/0.02A = 52.5 Ω (use 56 Ω) is required. The microcontroller GPIO can sink/source the 20mA. The low power consumption (40mW per LED) minimizes heat generation on the panel.

12. Operating Principle Introduction

This is a semiconductor light-emitting diode. When a forward voltage exceeding its characteristic forward voltage (V_F) is applied across the anode and cathode, electrons and holes are injected into the active region of the AlGaInP semiconductor chip. These charge carriers recombine, releasing energy in the form of photons. The specific composition of the AlGaInP alloy determines the bandgap energy, which defines the wavelength (color) of the emitted light—in this case, brilliant yellow (~591 nm). The water-clear epoxy resin encapsulant protects the chip and acts as a lens, shaping the light output to achieve the specified 120-degree viewing angle.

13. Technology Trends

The general trend in indicator LEDs is towards higher efficiency (more light output per watt), smaller package sizes for higher density boards, and increased integration of features like built-in current regulation or protection diodes. There is also a strong push for broader environmental compliance (beyond RoHS to include substances like PFAS) and enhanced reliability standards for automotive and industrial applications, as seen with this component's AEC-Q101 qualification. The use of advanced semiconductor materials like AlGaInP continues to provide superior performance for red, orange, and yellow colors compared to filtered or phosphor-converted white LEDs.