Top View LED 45-21 Series Technical Data Sheet - P-LCC-2 Package - 1.75-2.35V Forward Voltage - 50mA Max Current - Brilliant Red Color - English

1. Product Overview

The 45-21 series represents a family of Top View LEDs housed in a compact P-LCC-2 (Plastic Leaded Chip Carrier) surface-mount package. This device is engineered primarily as an optical indicator, featuring a colorless clear window and a white package body that enhances light reflection and diffusion. Its core design advantage lies in the wide viewing angle, achieved through an optimized inter-reflector design within the package. This characteristic makes it exceptionally well-suited for applications utilizing light pipes, where efficient light coupling from the LED source to the light guide is critical. The series is available in multiple colors, including the Brilliant Red variant detailed in this document, which utilizes AlGaInP semiconductor technology.

A key operational benefit is its low current requirement. With a typical forward current of 20mA for standard operation, it is ideal for power-sensitive applications such as portable and battery-operated equipment. The device is designed for compatibility with modern high-volume manufacturing processes, being suitable for vapor-phase reflow, infrared reflow, and wave soldering. It is also compatible with automatic pick-and-place equipment and is supplied on 8mm tape and reel for efficient assembly. The product is constructed with Pb-free materials and complies with relevant environmental regulations.

1.1 Core Advantages and Target Market

The primary advantages of this LED series stem from its package geometry and material selection. The wide viewing angle (typically 120 degrees) ensures visibility from a broad range of positions, which is essential for status indicators on consumer electronics, industrial panels, and communication devices. The optimized light coupling efficiency directly translates to brighter perceived output when used with light pipes, reducing the need for higher drive currents and saving power.

The target market is broad, encompassing telecommunications (for indicator and backlighting in phones and fax machines), consumer electronics, industrial controls, and automotive interiors. Its reliability and compatibility with automated processes make it a cost-effective choice for high-volume production. The low power consumption specifically targets the portable electronics segment, where extending battery life is a paramount design consideration.

2. In-Depth Technical Parameter Analysis

This section provides a detailed, objective interpretation of the key electrical, optical, and thermal parameters that define the LED's performance envelope and guide proper circuit design.

2.1 Absolute Maximum Ratings

The Absolute Maximum Ratings define the stress limits beyond which permanent damage to the device may occur. These are not conditions for normal operation.

• Reverse Voltage (V_R): 5V. Exceeding this voltage in reverse bias can cause junction breakdown.
• Forward Current (I_F): 50mA DC. The continuous current should not surpass this limit.
• Peak Forward Current (I_FP): 100mA, permissible only under pulsed conditions (duty cycle 1/10 at 1kHz). This allows for brief periods of higher brightness.
• Power Dissipation (P_d): 120mW. This is the maximum power the package can dissipate as heat without exceeding its thermal rating.
• Electrostatic Discharge (ESD): 2000V (Human Body Model). Proper ESD handling procedures are mandatory during assembly.
• Operating & Storage Temperature: Ranges from -40°C to +85°C (operating) and -40°C to +90°C (storage).
• Soldering Temperature: Withstands 260°C for 10 seconds (reflow) or 350°C for 3 seconds (hand soldering).

2.2 Electro-Optical Characteristics

These parameters are measured at a junction temperature (T_j) of 25°C under a standard test current of 20mA. They represent the typical performance.

• Luminous Intensity (I_v): Ranges from 450 mcd (min) to 900 mcd (max), with a typical tolerance of ±11%. This is the primary measure of perceived brightness.
• Viewing Angle (2θ_1/2): 120 degrees (typical). This is the full angle at which the luminous intensity drops to half of its peak axial value.
• Peak Wavelength (λ_p): 632 nm (typical). This is the wavelength at which the spectral power distribution is maximum.
• Dominant Wavelength (λ_d): Ranges from 617.5 nm to 633.5 nm, with a tolerance of ±1nm. This wavelength corresponds to the perceived color (Brilliant Red).
• Spectral Bandwidth (Δλ): 20 nm (typical). This indicates the spectral purity of the emitted red light.
• Forward Voltage (V_F): Ranges from 1.75V to 2.35V at 20mA, with a typical tolerance of ±0.1V. This is critical for designing the current-limiting resistor.
• Reverse Current (I_R): Maximum of 10 µA at a reverse bias of 5V, indicating good junction quality.

3. Binning System Explanation

To ensure consistency in mass production, LEDs are sorted into performance bins. Designers can specify bins to guarantee color and brightness uniformity across an application.

3.1 Luminous Intensity Binning

Intensity is categorized into three primary bins (U1, U2, V1) based on minimum and maximum values measured at I_F=20mA. For example, bin U1 covers 450-565 mcd, U2 covers 565-715 mcd, and V1 covers 715-900 mcd. Selecting a higher bin (e.g., V1) guarantees a brighter minimum output.

3.2 Dominant Wavelength Binning

The Brilliant Red color is grouped under 'Group A' and further divided into four wavelength bins: E4 (617.5-621.5 nm), E5 (621.5-625.5 nm), E6 (625.5-629.5 nm), and E7 (629.5-633.5 nm). A tighter bin selection (e.g., specifying only E5) ensures a more consistent shade of red across all LEDs in an assembly.

3.3 Forward Voltage Binning

Forward voltage is grouped under 'Group B' with three bins: 0 (1.75-1.95V), 1 (1.95-2.15V), and 2 (2.15-2.35V). While often less critical than color and brightness for indicators, specifying a voltage bin can be important for power supply design in large arrays or when driving LEDs in parallel without individual resistors.

4. Performance Curve Analysis

The provided characteristic curves offer valuable insights into the LED's behavior under varying conditions.

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

The curve shows the exponential relationship typical of a diode. At 25°C, the voltage rises sharply with current once the turn-on threshold is passed. This nonlinearity underscores the necessity of using a current-limiting resistor or constant-current driver, as a small change in voltage can cause a large, potentially damaging change in current.

4.2 Relative Luminous Intensity vs. Forward Current

This curve demonstrates that light output increases approximately linearly with current over a range, but will eventually saturate at higher currents due to thermal and efficiency effects. Operating at the recommended 20mA provides a good balance of brightness and efficiency.

4.3 Relative Luminous Intensity vs. Ambient Temperature

The luminous intensity decreases as the ambient temperature increases. This derating curve is crucial for applications operating in elevated temperature environments. Designers must account for this reduction to ensure sufficient brightness is maintained under all operating conditions.

4.4 Spectral Distribution

The spectrum plot confirms the monochromatic nature of the AlGaInP LED, with a single, narrow peak centered around 632 nm, producing a saturated Brilliant Red color without significant emission in other wavelength bands.

4.5 Radiation Pattern (Polar Diagram)

The diagram visually confirms the wide, Lambertian-like emission pattern. The intensity is nearly uniform across a wide central region, dropping off gradually towards the edges, which is ideal for wide-angle viewing.

5. Mechanical & Packaging Information

5.1 Package Outline and Dimensions

The P-LCC-2 package has a compact footprint. Critical dimensions include the overall length, width, and height, as well as the lead spacing and size. A polarity indicator (typically a notch or a dot on the package or a chamfered corner) identifies the cathode. The datasheet provides a recommended solder pad land pattern to ensure reliable solder joint formation and proper alignment during reflow.

5.2 Tape and Reel Specifications

The device is supplied on 8mm carrier tape, wound onto standard reels. The tape dimensions (pocket size, pitch) and reel dimensions (hub diameter, flange diameter) are specified to be compatible with automated assembly equipment. Each reel contains 2000 pieces.

5.3 Moisture Sensitivity and Packaging

The LEDs are packaged in a moisture-resistant aluminum bag with a desiccant to prevent moisture absorption, which could cause \"popcorning\" (package cracking) during the high-temperature reflow soldering process. The label on the bag contains critical information such as the moisture sensitivity level (implied by the packaging), quantity, and part number.

6. Soldering & Assembly Guidelines

6.1 Reflow Soldering Parameters

The device is rated for a peak reflow temperature of 260°C for a maximum of 10 seconds. This aligns with standard Pb-free reflow profiles. The thermal mass of the PCB and the specific profile (ramp-up, soak, peak, cool-down) must be controlled to stay within this limit and avoid thermal shock.

6.2 Storage and Handling Precautions

• Before Opening: The moisture-proof bag should be stored at ≤30°C and ≤70% RH. The components should be used within one year of the bag seal date.
• After Opening: If not used immediately, components exposed to ambient humidity may require baking before soldering according to standard IPC/JEDEC guidelines to remove absorbed moisture.
• ESD Protection: Standard ESD precautions (grounded workstations, wrist straps) must be observed during handling.

7. Application Design Recommendations

7.1 Typical Application Circuits

The most common drive circuit is a series current-limiting resistor connected to a voltage source (V_CC). The resistor value is calculated as R = (V_CC - V_F) / I_F. Using the maximum V_F from the datasheet (2.35V) in this calculation ensures the current never exceeds the desired I_F even with part-to-part variation. For example, with a 5V supply and a target I_F of 20mA: R = (5V - 2.35V) / 0.02A = 132.5Ω. A standard 130Ω or 150Ω resistor would be appropriate.

7.2 Design Considerations for Light Pipe Applications

When coupling to a light pipe, align the LED centrally under the pipe's input surface. The wide viewing angle of this LED helps fill the input aperture of the pipe. The distance between the LED dome and the light pipe should be minimized to reduce light loss. The white package helps reflect light that would otherwise be lost downwards back into the emitting direction, improving overall coupling efficiency. Mechanical drawings should account for the LED's height and recommended keep-out areas.

7.3 Thermal Management

While the power dissipation is low, continuous operation at maximum current (50mA) in high ambient temperatures may approach the device's limits. For such use cases, ensuring adequate PCB copper area around the LED's thermal pads (if any) or thermal vias can help dissipate heat and maintain lower junction temperature, preserving luminous output and long-term reliability.

8. Reliability and Quality Assurance

The datasheet outlines a comprehensive set of reliability tests performed with a 90% confidence level and 10% Lot Tolerance Percent Defective (LTPD). These tests simulate harsh operating and storage conditions to ensure field reliability.

• Reflow Soldering Resistance: Verifies the package can withstand the soldering process.
• Temperature Cycling & Thermal Shock: Tests robustness against mechanical stress induced by repeated temperature changes.
• High/Low Temperature Storage: Assesses long-term stability under extreme non-operating conditions.
• DC Operating Life: A 1000-hour life test at rated current (20mA) and temperature (25°C).
• High Temperature/Humidity Operating Life (85°C/85% RH): Accelerated test for moisture resistance and corrosion under bias.

Passing these tests indicates a robust product suitable for demanding commercial and industrial applications.

9. Frequently Asked Questions (FAQ)

9.1 Why is a current-limiting resistor absolutely necessary?

The LED's I-V characteristic is exponential. A small increase in supply voltage above the LED's forward voltage drop causes a very large, potentially destructive increase in current. The resistor provides a linear, predictable voltage drop that stabilizes the current, protecting the LED from over-current conditions caused by normal voltage tolerances or transients.

9.2 Can I drive this LED directly from a microcontroller GPIO pin?

Yes, but with important caveats. The GPIO pin must be configured as an output. You must still include a series resistor. Furthermore, you must ensure the microcontroller's pin can source (or sink, depending on your circuit configuration) the required 20mA continuously, which is at or beyond the limit for some general-purpose I/O pins. Consult the microcontroller datasheet. Using a transistor as a switch is often a safer and more flexible option for higher currents or when driving multiple LEDs.

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

Peak Wavelength (λ_p): The single wavelength where the spectral power output is physically the highest. Dominant Wavelength (λ_d): The wavelength of monochromatic light that would be perceived by the human eye as having the same color as the LED's output. For a monochromatic LED like this red one, they are very close. Dominant wavelength is generally the more relevant parameter for color specification and binning.

9.4 How do I interpret the bin codes on the reel label?

The label uses codes like CAT, HUE, and REF. 'CAT' corresponds to the Luminous Intensity Bin (e.g., U1, V1). 'HUE' corresponds to the Dominant Wavelength Bin (e.g., E5, E6). 'REF' corresponds to the Forward Voltage Bin (e.g., 0, 1, 2). Knowing these codes allows you to verify you have received the specific performance grade you ordered.