Top View LED 67-21 Series Datasheet - Package 3.2x2.8x1.9mm - Forward Voltage 1.75-2.35V - Brilliant Yellow - 100mW Power - English Technical Document

1. Product Overview

The 67-21 series represents a family of surface-mount Top View LEDs designed for indicator and backlighting applications. This specific variant, identified by the part number suffix indicating brilliant yellow emission, is engineered to provide reliable performance in a compact, industry-standard P-LCC-2 package. The device features a white package body with a colorless clear window, which contributes to its wide viewing angle and makes it particularly suitable for use with light pipes to guide illumination to specific areas on a panel or display.

The core advantage of this LED lies in its optimized optical design. An internal reflector within the package enhances light coupling efficiency, ensuring bright and uniform output. Furthermore, its low forward current requirement makes it an ideal choice for battery-powered or power-sensitive portable equipment, where minimizing energy consumption is critical. The device is fully compliant with lead-free (Pb-free) manufacturing requirements and adheres to RoHS directives, making it suitable for global markets with strict environmental regulations.

2. Technical Parameter Deep-Dive

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. They are not intended for normal operation.

• Reverse Voltage (V_R): 5 V. Exceeding this voltage in reverse bias can cause junction breakdown.
• Continuous Forward Current (I_F): 50 mA. The maximum DC current that can be applied continuously.
• Peak Forward Current (I_FP): 120 mA. This is the maximum allowable pulsed current, specified under a duty cycle of 1/10 at 1 kHz. It is crucial for applications involving brief, high-intensity flashes.
• Power Dissipation (P_d): 100 mW. This is the maximum power the package can dissipate as heat, calculated as Forward Voltage (V_F) multiplied by Forward Current (I_F).
• Electrostatic Discharge (ESD) Human Body Model (HBM): 2000 V. This rating indicates the LED's sensitivity to static electricity. Proper ESD handling procedures are necessary during assembly.
• Operating Temperature (T_opr): -40°C to +85°C. The ambient temperature range over which the device is guaranteed to meet its electro-optical specifications.
• Storage Temperature (T_stg): -40°C to +90°C.
• Soldering Temperature: The device can withstand reflow soldering with a peak temperature of 260°C for up to 10 seconds, or hand soldering at 350°C for up to 3 seconds.

2.2 Electro-Optical Characteristics

These parameters are measured at a standard test condition of 25°C ambient temperature and a forward current (I_F) of 20 mA, which is the typical operating point.

• Luminous Intensity (I_V): Ranges from a minimum of 140 mcd to a maximum of 360 mcd. The typical value falls within this range, and specific brightness is determined by the binning process.
• Viewing Angle (2θ_1/2): 120 degrees (typical). This is the full angle at which the luminous intensity drops to half of its maximum value (on-axis). The wide angle is a key feature for applications requiring visibility from off-axis positions.
• Peak Wavelength (λ_p): 591 nm (typical). The wavelength at which the spectral power distribution is at its maximum.
• Dominant Wavelength (λ_d): 588.5 nm to 594.5 nm. This is the single-wavelength perception of the LED's color by the human eye and is the primary parameter for color binning.
• Spectral Bandwidth (Δλ): 15 nm (typical). The width of the emitted spectrum at half its maximum power (Full Width at Half Maximum - FWHM).
• Forward Voltage (V_F): 1.75 V to 2.35 V at I_F=20mA. The voltage drop across the LED when it is conducting. This range is important for designing the current-limiting circuitry.
• Reverse Current (I_R): Maximum 10 μA at V_R=5V. A very low leakage current when the LED is reverse-biased.

3. Binning System Explanation

To ensure color and brightness consistency in production, LEDs are sorted into bins based on key parameters. The 67-21 series uses a three-dimensional binning system.

3.1 Dominant Wavelength Binning (HUE)

This determines the precise shade of yellow. The bins are labeled with group "B" and codes D4 and D5.

• Bin D4: Dominant Wavelength from 588.5 nm to 591.5 nm.
• Bin D5: Dominant Wavelength from 591.5 nm to 594.5 nm.

A tolerance of ±1nm is applied to these bin limits.

3.2 Luminous Intensity Binning (CAT)

This determines the brightness level. The bins are defined by codes R2, S1, S2, and T1.

• Bin R2: 140 mcd to 180 mcd.
• Bin S1: 180 mcd to 225 mcd.
• Bin S2: 225 mcd to 285 mcd.
• Bin T1: 285 mcd to 360 mcd.

A tolerance of ±11% is applied to the luminous intensity.

3.3 Forward Voltage Binning (REF)

This groups LEDs with similar electrical characteristics, which can simplify power supply design. The bins are labeled with group "B" and codes 0, 1, and 2.

• Bin 0: V_F from 1.75 V to 1.95 V.
• Bin 1: V_F from 1.95 V to 2.15 V.
• Bin 2: V_F from 2.15 V to 2.35 V.

A tolerance of ±0.1V is applied to the forward voltage.

4. Performance Curve Analysis

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

4.1 Relative Luminous Intensity vs. Ambient Temperature

This curve shows that the light output of the LED decreases as the ambient temperature increases. At the maximum operating temperature of +85°C, the relative luminous intensity is significantly lower than at 25°C. This thermal derating must be accounted for in designs where high ambient temperatures are expected, such as in automotive applications or near heat-generating components.

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

The I-V curve is non-linear, typical of a diode. It shows the relationship between the current flowing through the LED and the voltage across it. The curve is essential for selecting an appropriate current-limiting resistor or designing a constant-current driver. The "knee" of the curve, where conduction begins, is around 1.6V to 1.8V for this device.

4.3 Relative Luminous Intensity vs. Forward Current

This curve demonstrates that light output increases with forward current, but not in a perfectly linear fashion, especially at higher currents. It also highlights the importance of operating within the Absolute Maximum Ratings; driving the LED beyond its specified current will not yield proportional increases in brightness and will generate excessive heat, reducing lifespan.

4.4 Spectrum Distribution

The spectral graph shows a single, dominant peak centered around 591 nm, confirming the brilliant yellow color. The narrow bandwidth indicates good color purity. There is minimal emission in the deep red or green regions, which is desirable for a pure yellow indicator.

4.5 Radiation Pattern

The polar diagram visually confirms the wide 120° viewing angle. The intensity distribution is roughly Lambertian (cosine-like), meaning it is brightest when viewed head-on and gradually decreases towards the edges of the viewing cone.

5. Mechanical and Packaging Information

5.1 Package Dimensions

The LED is housed in a P-LCC-2 (Plastic Leaded Chip Carrier) package. Key dimensions include a body size of approximately 3.2mm x 2.8mm, with a height of 1.9mm. The package features two gull-wing leads for surface mounting. The cathode is typically identified by a notch or a green marking on the package. Detailed dimensional drawings with tolerances of ±0.1mm are provided in the datasheet for PCB footprint design.

5.2 Polarity Identification

Correct polarity is critical for operation. The package incorporates visual markers. The cathode (-) lead is often indicated by a green dot or a small notch on the package body. Designers must cross-reference the package drawing with the recommended PCB footprint to ensure the anode and cathode pads are correctly oriented.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Parameters

The device is compatible with vapor-phase and infrared reflow processes. The recommended profile has a peak temperature of 260°C, which should not be exceeded for more than 10 seconds. This is a standard profile for lead-free (SnAgCu) solder pastes. Preheating and cooling rates should be controlled to minimize thermal stress on the package.

6.2 Hand Soldering

If hand soldering is necessary, the iron tip temperature should not exceed 350°C, and contact time with each lead should be limited to a maximum of 3 seconds. A heat sink may be used on the lead between the joint and the package body to protect the LED die from excessive heat.

6.3 Storage Conditions

The LEDs are packaged in moisture-resistant barrier bags with desiccant to prevent moisture absorption, which can cause "popcorning" (package cracking) during reflow. Once the sealed bag is opened, the components should be used within a specified time frame (typically 168 hours at factory conditions) or rebaked according to the moisture sensitivity level (MSL) specification, which should be obtained from the manufacturer.

7. Packaging and Ordering Information

7.1 Tape and Reel Specifications

The components are supplied on 8mm wide embossed carrier tape. Each reel contains 2000 pieces. Detailed dimensions for the carrier tape pockets and the reel are provided to ensure compatibility with automated pick-and-place equipment.

7.2 Label Explanation and Part Numbering

The reel label contains critical information for traceability and correct assembly:

• CAT: The Luminous Intensity bin code (e.g., S1, T1).
• HUE: The Dominant Wavelength bin code (e.g., D4, D5).
• REF: The Forward Voltage bin code (e.g., 0, 1, 2).
• Part Number (PN), Customer Part Number (CPN), Quantity (QTY), and Lot Number for tracking.

The full part number (e.g., 67-21/Y2C-BR2T1B/2T) encodes the series, color, brightness bin, and other attributes specific to the manufacturer's system.

8. Application Suggestions

8.1 Typical Application Scenarios

• Automotive Electronics: Backlighting for dashboard instruments, switches, and control panels. The wide viewing angle and reliability across a wide temperature range make it suitable for this demanding environment.
• Telecommunication Equipment: Status indicators and keypad backlighting in phones, fax machines, and networking hardware.
• Consumer Electronics: Power indicators, button illumination, and status lights in portable devices, home appliances, and audio/video equipment.
• General Panel Indicators: Any application requiring a bright, reliable, and compact status indicator.

8.2 Design Considerations

• Current Limiting: Always use a series resistor or constant-current driver to set the forward current. Calculate the resistor value using R = (V_supply - V_F) / I_F. Use the maximum V_F from the datasheet to ensure the current does not exceed the limit even with part-to-part variation.
• Thermal Management: While the power dissipation is low, ensure adequate PCB copper area or thermal vias under the thermal pad (if present) to conduct heat away, especially in high ambient temperature applications or when driving at higher currents.
• Light Pipe Coupling: For light pipe applications, position the LED as close as possible to the entrance of the light pipe. The wide viewing angle helps capture more light, but precise alignment is still key to maximizing efficiency and achieving uniform illumination at the output.
• ESD Protection: Implement ESD protection on input lines if the LED is directly accessible to users (e.g., on a front panel). During handling and assembly, follow standard ESD precautions.

9. Technical Comparison and Differentiation

The 67-21 series differentiates itself in the market of SMD indicator LEDs through several key features. Compared to older, smaller packages (like 0402 or 0603), it offers significantly higher light output and a much wider viewing angle due to its larger die and optimized internal reflector. Against other P-LCC-2 packages, its specific combination of a brilliant yellow color (based on AlGaInP material for high efficiency), well-defined binning structure for consistency, and robust specifications for reflow soldering make it a reliable choice for volume production. Its low forward voltage requirement is also a distinct advantage in battery-powered designs, as it reduces the voltage headroom needed from the power source, potentially extending battery life.

10. Frequently Asked Questions (Based on Technical Parameters)

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

Peak Wavelength (λ_p) is the physical wavelength where the LED emits the most optical power. Dominant Wavelength (λ_d) is a calculated value that represents the single wavelength of monochromatic light that would appear to have the same color to the human eye. Dominant wavelength is more relevant for color perception and is used for binning.

10.2 Can I drive this LED with a 3.3V supply without a resistor?

No, this is not recommended and is likely to destroy the LED. An LED is a current-driven device. Without a current-limiting mechanism (a resistor or active driver), connecting it directly to a voltage source like 3.3V will cause excessive current to flow, far exceeding the 50mA maximum rating, leading to immediate overheating and failure.

10.3 Why does the luminous intensity decrease at high temperature?

This is a fundamental characteristic of semiconductor light sources. As temperature increases, non-radiative recombination processes within the semiconductor material become more dominant, reducing the internal quantum efficiency (the number of photons generated per electron). This results in lower light output for the same drive current.

10.4 How do I select the right bin for my application?

Selection depends on your requirements:

• For color consistency across multiple LEDs in a product, specify a tight HUE bin (e.g., only D4).
• For brightness consistency, specify a tight CAT bin (e.g., only T1 for highest brightness).
• For simplified power supply design in constant-voltage systems, specifying a tight REF bin (e.g., only Bin 1) ensures more predictable current draw.

Consult with the component supplier for availability and cost implications of specific bin combinations.

11. Practical Design Case Study

Scenario: Designing a status indicator for a portable medical device. The indicator must be clearly visible in various lighting conditions, consume minimal power to maximize battery life, and withstand occasional cleaning with disinfectants.

Implementation: The 67-21 brilliant yellow LED is selected. A light pipe is designed to channel light from the LED, mounted on the main PCB, to a small window on the device's sealed front panel. This protects the LED from physical contact and liquids. The drive circuit uses a GPIO pin from a microcontroller, a 100Ω current-limiting resistor connected to a 3.3V rail, resulting in a forward current of approximately (3.3V - 2.0V)/100Ω = 13mA, well within the safe operating area. This provides ample brightness while minimizing power consumption. The wide viewing angle of the LED ensures the light pipe is efficiently filled, giving a uniform glow at the panel.

12. Operating Principle Introduction

This LED is based on an Aluminum Gallium Indium Phosphide (AlGaInP) semiconductor chip. When a forward voltage exceeding the diode's turn-on threshold is applied, electrons are injected from the n-type region and holes from the p-type region into the active region. These charge carriers recombine, releasing energy in the form of photons (light). The specific composition of the AlGaInP alloy determines the bandgap energy of the semiconductor, which directly dictates the wavelength (color) of the emitted light. For brilliant yellow, the bandgap corresponds to photons with energy around 2.1 eV (wavelength ~590 nm). The generated light is then extracted through the top of the chip, shaped and directed by the internal reflector and the clear epoxy lens of the P-LCC-2 package.

13. Technology Trends and Developments

The general trend in SMD indicator LEDs like the 67-21 series is towards higher efficiency (more light output per milliampere of current), which allows for either brighter indicators or lower power consumption. There is also a drive for improved color consistency and tighter binning from wafer to wafer. Packaging technology continues to evolve, with potential future developments including even thinner profiles for space-constrained applications and materials with higher thermal conductivity to better manage heat at higher drive currents. Furthermore, integration with onboard control, such as having a tiny IC for PWM dimming or color sequencing within the same package, is a growing trend in the broader LED market, though it may be more relevant for multi-color or addressable LEDs than for standard single-color indicators.