📌 Product Overview
The XL-S2008RHIRC is a high-efficiency, bi-color SMD LED designed specifically for optical biosensing applications. 🩸 It integrates a Red (660nm) and an Infrared (870nm) emitter into a compact 2008 (2.0mm x 0.8mm x 0.4mm) surface-mount package, making it ideal for space-constrained wearable devices.
This component targets the rapidly expanding market of consumer and professional health monitoring, such as smartwatches and medical-grade pulse oximeters. ⚙️ The design focus is on providing stable optical output power (PO) within a standard SMT process flow, ensuring reliable performance for SpO2 and heart rate detection algorithms.
💡 Typical Applications
Based on its dual-peak wavelength and compact form factor, the XL-S2008RHIRC is engineered for the following scenarios:
- Pulse Oximetry (SpO2): Utilizing the ratio of Red (660nm) and IR (870nm) absorption to calculate blood oxygen saturation levels.
- Heart Rate Monitoring (PPG): 📈 Photoplethysmography applications requiring green or red light for vascular pulse detection in smart wearables.
- Medical Diagnostics: Integration into professional-grade finger-clip or wearable oximeters for continuous patient monitoring.
- Compact Electronics: Suitable for PCB designs where board space is at a premium but high optical output is required.
⚡ Key Technical Specifications
The table below details the electro-optical characteristics at $T_a = 25^\circ C$:
| Parameter | Symbol | Red (660nm) | Infrared (870nm) | Unit | Condition |
|---|---|---|---|---|---|
| Forward Voltage | $V_F$ | Max 2.5 | Max 1.7 | V | $I_F = 20\text{mA}$ |
| Peak Wavelength | $\lambda_p$ | 660 (Typ) | 870 (Typ) | nm | $I_F = 20\text{mA}$ |
| Optical Power | $P_O$ | 8.5 / 10.5 (Typ) | 6 / 7.2 (Typ) | mW | $I_F = 20\text{mA}$ |
| Pulse Power | $P_O$ | Min 75 | Min 50 | mW | $200\text{mA}, 1/10 \text{ Duty}$ |
| Half Viewing Angle | $\theta_{1/2}$ | $\pm 60$ | $\pm 60$ | deg | - |
| Reverse Current | $I_R$ | - | 10 (Max) | $\mu$A | $V_R = 5\text{V}$ |
🔒 Absolute Maximum Ratings & Process Limits
Exceeding these ratings may cause permanent device failure or degradation. 🚫 Thermal management is critical to maintaining optical output and lifespan.
| Parameter | Symbol | Value | Unit | Notes |
|---|---|---|---|---|
| Forward Current (DC) | $I_F$ | 50 | mA | Per Chip |
| Pulse Forward Current | $I_{FP}$ | 200 | mA | Pulse width 0.5ms, Duty 1/10 |
| Reverse Voltage | $V_R$ | 5 | V | |
| Operating Temperature | $T_{OPR}$ | -40 ~ +85 | $^\circ$C | |
| Storage Temperature | $T_{STR}$ | -40 ~ +100 | $^\circ$C | |
| Soldering Temp | $T_{SOL}$ | 260 | $^\circ$C | $\le 6\text{s}$ |
| Moisture Sensitivity | MSL | Level 3 | Floor life: 168 hours @ 30C/60%RH |
🏗️ Package, Dimensions & Assembly Notes
- Form Factor: The 2008 metric package (2.0mm L x 0.8mm W x 0.4mm H) allows for high-density placement on rigid or flexible PCBs.
- Soldering Compatibility: Designed for standard reflow soldering processes. Follow the recommended profile with a peak temperature not exceeding 260°C for a maximum of 6 seconds.
- Packaging: 📦 The component is supplied in EIA standard compliant tape and reel packaging, optimized for high-speed automated SMT pick-and-place machines.
- Handling: Given MSL Level 3, if the bag is opened, the components must be soldered within 168 hours or baked before assembly to prevent popcorning.
🚀 Sourcing & Supply Considerations
- Supply Chain Status: Verify current lead times for the bi-color configuration, as Red/IR combinations often have different availability cycles than standard white LEDs.
- Quality Standards: Ensure supplied stock adheres to ROHS environmental requirements.
- Procurement Note: When sourcing, confirm the specific binning for wavelength and forward voltage to maintain consistency in your optical algorithms.
- Sample Verification: 👇 Always request a sample lot to validate the spectral absorption ratio against your specific sensor hardware before bulk ordering.
❓ FAQ
Q: What is the typical forward voltage for each color?
A: For the Red chip, the forward voltage is typically 2.5V at 20mA. For the Infrared chip, it is significantly lower, typically 1.7V at 20mA.
Q: Can this LED be used for continuous DC operation at 50mA?
A: Yes, the Absolute Maximum Rating for DC forward current is 50mA. However, thermal management must be considered to prevent exceeding the junction temperature limits.
Q: What are the storage requirements to prevent moisture damage?
A: The XL-S2008RHIRC is rated MSL 3. If the moisture barrier bag is opened, components have a floor life of 168 hours (1 week) before requiring re-baking or reflow.
Q: Is this component suitable for flexible circuits (FPC) in wearables?
A: Yes, the 2008 (0808 metric) package is small and lightweight, making it highly suitable for FPCs used in wristbands and smartwatches, provided the reflow profile is carefully controlled.
Q: What is the advantage of using Red and Infrared together?
A: This combination is essential for Pulse Oximetry. Oxygenated hemoglobin absorbs more Infrared light and allows more Red light to pass through, while deoxygenated hemoglobin does the opposite, enabling the calculation of SpO2 levels.
