Professional IC Distribution & Technical Solutions

The ELS-321RDB is a surface-mount LED manufactured by EVERLIGHT. Below are its specifications, descriptions, and features:

Specifications:

• Color: Red
• Lens Appearance: Water Clear
• Forward Voltage (Vf): 1.8V (Typical)
• Forward Current (If): 20mA
• Luminous Intensity (Iv): 50mcd (Minimum)
• Viewing Angle: 120°
• Wavelength (λD): 625nm (Typical)
• Power Dissipation (Pd): 75mW
• Operating Temperature Range: -40°C to +85°C
• Storage Temperature Range: -40°C to +100°C
• Package Type: SMD (Surface-Mount Device)
• Dimensions (L x W x H): 3.2mm x 1.6mm x 1.1mm

Descriptions:

• The ELS-321RDB is a high-efficiency red LED designed for surface-mount applications.
• It features a water-clear lens for enhanced brightness and visibility.
• Suitable for automotive, consumer electronics, indicators, and backlighting applications.
• Compliant with RoHS and Halogen-Free standards.

Features:

• High brightness with a luminous intensity of 50mcd (min).
• Wide viewing angle (120°) for better visibility.
• Low power consumption with a forward voltage of 1.8V (Typ).
• Compact SMD package for space-saving PCB designs.
• Reliable performance across a broad temperature range (-40°C to +85°C).

This LED is ideal for applications requiring bright, energy-efficient indicators in a compact form factor.

# Technical Analysis of the ELS-321RDB Infrared Emitter

## Practical Application Scenarios

The ELS-321RDB, manufactured by EVERLIGHT, is a high-performance infrared (IR) emitter designed for applications requiring reliable optical signaling. Its key characteristics—including a peak wavelength of 940 nm, high radiant intensity, and compact package—make it suitable for the following use cases:

1. Infrared Remote Control Systems

The emitter is widely used in consumer electronics, such as TV remotes, air conditioners, and set-top boxes. Its high efficiency ensures long-range signal transmission with minimal power consumption.

2. Proximity and Object Detection

In industrial automation, the ELS-321RDB pairs with photodetectors to detect object presence or motion, commonly found in conveyor belt systems and safety interlocks.

3. Optical Data Communication

Short-range IR data transmission, such as in legacy IrDA applications or secure point-to-point communication, benefits from the emitter’s fast response time and stable output.

4. Night Vision Illumination

Surveillance cameras with IR illumination leverage the ELS-321RDB’s spectral alignment with silicon-based sensors, enhancing low-light visibility without visible glow.

## Common Design-Phase Pitfalls and Avoidance Strategies

1. Thermal Management Issues

Excessive forward current can lead to overheating, reducing emitter lifespan.

*Mitigation:* Adhere to the absolute maximum ratings (e.g., 100 mA forward current) and implement heat dissipation techniques, such as PCB thermal pads or pulsed driving.

2. Optical Misalignment

Poor alignment with detectors causes signal loss, particularly in proximity sensing.

*Mitigation:* Use mechanical housings or lens attachments to ensure precise beam directionality.

3. Electrical Overstress

Voltage spikes or reverse bias can damage the diode.

*Mitigation:* Incorporate current-limiting resistors and transient voltage suppressors (TVS) in series.

4. Ambient Light Interference

Sunlight or artificial light sources may introduce noise.

*Mitigation:* Employ modulated signals (e.g., 38 kHz carrier) and optical filters to improve signal-to-noise ratio.

## Key Technical Considerations for Implementation

1. Forward Current and Duty Cycle

Operate within the recommended DC forward current (typically 50–70 mA) or use pulsed mode (<1% duty cycle for higher peak currents) to maximize efficiency.

2. Viewing Angle

The ELS-321RDB’s half-angle (e.g., ±20°) affects coverage. Narrower angles suit long-range applications, while wider angles benefit area illumination.

3. Solder Process Compatibility

The component is compatible with reflow soldering (JEDEC J-STD-020 compliant), but excessive thermal profiles should be avoided to prevent lens degradation.

4. ESD Sensitivity

As a semiconductor device, ESD precautions (e.g., grounded workstations) are critical during handling and assembly.

By addressing these factors, designers can optimize the ELS-321RDB’s performance while avoiding operational failures.