Infrared LED 850nm Specification - Size 2.8x3.5x2.6mm - Voltage 1.4V - Power 80mW - REFOND RF-P28Q3-IRJ-FT

1. Product Overview

The RF-P28Q3-IRJ-FT is a high-reliability infrared LED in a PPA (Polyphthalamide) package, measuring 2.80mm x 3.50mm x 2.60mm. It emits at a peak wavelength of 850nm, making it ideal for security monitoring, infrared illumination for cameras, and machine vision systems. This LED features low forward voltage (typical 1.4V at 50mA), lead-free reflow soldering compatibility, and is RoHS compliant with moisture sensitivity level 5.

2. Technical Parameter Analysis

2.1 Electrical and Optical Characteristics

At a test temperature of 25°C and forward current of 50mA, the LED exhibits a forward voltage of typically 1.4V (max 1.6V). The peak wavelength is 850nm with a spectral bandwidth (Δλ) of 30nm. Total radiant flux (Φe) ranges from 14mW (min) to 28mW (typical), ensuring sufficient optical output for near-infrared applications. Reverse current is negligible (max 10μA at 5V reverse voltage). The viewing angle (2θ1/2) is 17°, providing a narrow beam suitable for focused illumination.

2.2 Thermal Resistance and Maximum Ratings

The thermal resistance from junction to solder point (RTHJ-S) is 50°C/W, indicating moderate heat dissipation. Absolute maximum ratings include power dissipation of 80mW, forward current of 50mA, and junction temperature up to 105°C. The LED can withstand ESD up to 2000V (HBM). Operating and storage temperatures range from -40°C to +85°C.

3. Binning System

Based on the label specification, each reel is binned according to total radiant flux (Φe), peak wavelength (WLP), and forward voltage (VF). The bin code (BIN CODE) encodes these parameters to ensure consistency within a shipment. For example, the Φe bin may group LEDs with similar light output, while the wavelength bin ensures narrow spectral tolerance for applications requiring uniform emission.

4. Performance Curve Analysis

4.1 Forward Voltage vs. Forward Current

The forward voltage increases with current, typically from 1.3V at 10mA to 1.6V at 60mA. This nonlinear relationship must be considered when designing constant-current drivers to avoid thermal runaway.

4.2 Temperature Characteristics

Relative intensity drops as junction temperature rises, losing about 25% at 105°C compared to 25°C. The forward current vs. temperature derating curve shows that maximum current must be reduced at elevated ambient temperatures to keep the junction below 105°C.

4.3 Spectral Distribution

The emission spectrum peaks at 850nm with a full-width at half-maximum of 30nm. Minimal emission outside 800-900nm ensures compatibility with silicon-based CMOS sensors commonly used in surveillance cameras.

4.4 Radiation Pattern

The half-power angle is 17°, with a relatively narrow beam. The radiation diagram shows a smooth Gaussian-like distribution, enabling efficient light delivery in applications requiring controlled illumination.

5. Mechanical and Packaging Information

5.1 Package Dimensions

The package is 2.80mm (length) x 3.50mm (width) x 2.60mm (height). All dimensions have a tolerance of ±0.2mm unless otherwise noted. The bottom view shows a polarity mark (cathode notch), and the anode/cathode pads are clearly identified. The soldering pattern recommended in the drawing (1.85mm x 1.25mm pads with 1.80mm spacing) ensures proper thermal and electrical connection.

5.2 Polarity and Handling

The LED has a visible polarity marking on the top view (Fig.1-2). Correct orientation is critical; reverse bias can cause immediate failure or long-term degradation.

6. Soldering and Assembly Guide

6.1 Reflow Soldering Profile

Reflow soldering should be performed per the specified profile: preheat from 160°C to 200°C for 60-120 seconds, ramp-up of max 3°C/s to a peak temperature of 260°C (max 5 seconds above 255°C), then cool down at max 6°C/s. Only two reflow cycles are permitted, and if more than 24 hours pass between cycles, the LEDs must be re-baked.

6.2 Hand Soldering and Repair

For hand soldering, use an iron set below 300°C for less than 3 seconds. Repair should be avoided; if necessary, use a double-head soldering iron and confirm that LED characteristics are not degraded.

7. Packaging and Ordering Information

The LED is packaged in tape and reel with 3000 pieces per reel. Reel dimensions: diameter 330.2mm, hub 79.5mm, width 12.7mm. Each reel is sealed in a moisture barrier bag with a desiccant and a humidity indicator card. Storage conditions: before opening the bag, store at ≤30°C and ≤75% RH for up to 1 year; after opening, use within 48 hours at ≤30°C and ≤60% RH. If the bag is opened beyond this time, bake at 60±5°C for 24 hours before use.

8. Application Recommendations

The narrow 17° beam and 850nm peak wavelength make this LED ideal for long-range IR illumination in security cameras, license plate recognition, and night vision systems. It can be arrayed in series/parallel configurations, but careful current balancing and thermal management are required to stay within maximum ratings. A series resistor per LED string is strongly recommended to prevent current hogging.

9. Technical Comparison

Compared to similar 850nm LEDs in 2835 packages, the RF-P28Q3-IRJ-FT offers a competitive low forward voltage (1.4V typical) which reduces power dissipation in constant-current drivers. Its narrow 17° viewing angle provides higher on-axis intensity than wider-angle emitters, making it suitable for spot illumination. The PPA package provides better thermal stability than some lower-cost epoxy packages, though thermal resistance of 50°C/W is moderate.

10. Frequently Asked Questions

Q: Can this LED be driven at 100mA for short pulses?
A: The absolute maximum forward current is 50mA DC. Pulse operation (e.g., 1/10 duty, 0.1ms) may allow higher peak current, but junction temperature must never exceed 105°C.

Q: What is the recommended ESD protection during handling?
A: The LED has a 2000V HBM rating, but proper ESD precautions (grounded workstations, conductive trays) are strongly advised.

Q: How does the LED behave under reverse bias?
A: Reverse voltage should not exceed 5V. At 5V reverse voltage, maximum reverse current is 10μA; prolonged reverse bias can cause migration and failure.

11. Practical Design Case

In a typical surveillance camera IR illuminator, eight LEDs are arranged in two parallel strings of four series. Each string is driven at 50mA with a 3.3V supply and a 6.8Ω resistor to limit current. The total power dissipation (~1.28W) requires a small aluminum PCB with thermal vias to keep the junction temperature below 85°C in ambient conditions. The 17° beam is focused using a narrow-angle lens to achieve over 100m effective illumination range.

12. Operating Principle

This LED is a semiconductor diode that emits light at 850nm when forward biased. The active region consists of III-V compound materials (typically AlGaAs or GaAs) that convert electrical energy into near-infrared photons. The PPA (Polyphthalamide) package provides mechanical protection, heat dissipation, and a lensing effect to shape the radiation pattern.

13. Development Trends

Future trends in 850nm IR LEDs include higher wall-plug efficiency to reduce heat generation, smaller packages (e.g., 1.6x1.6mm) for high-density arrays, and improved ESD robustness. The demand for IR illumination in AI-based surveillance, autonomous vehicles, and gesture recognition is pushing manufacturers to increase radiant flux while maintaining narrow spectral bandwidth.