📌 Product Overview
The XL-3528PDC is a standard 3528 package SMD infrared phototransistor tailored for automated assembly. It utilizes a transparent NPN silicon epoxy encapsulation to maximize light transmission while providing robust environmental protection. 🏗️ Designed primarily for receiving circuits in optoelectronic switching, it offers a compact form factor compatible with high-volume infrared reflow soldering processes.
Its core engineering focus lies on detecting 940nm infrared signals with high sensitivity in low-power circuits. The device is specifically constructed to meet ROHS compliance and withstand standard MSL 3 moisture sensitivity levels, ensuring stability during SMT production runs.
💡 Typical Applications
Based on the XL-3528PDC's spectral sensitivity and saturation voltage characteristics, this component is ideally suited for the following precision sensing scenarios:
- 🏠 Smart Home & Appliances: Iris recognition systems and household appliance sensors requiring non-contact detection.
- 🛡️ Safety & Security: Smoke detectors and fire alarm systems where reliable infrared sensing is critical.
- 🔧 Industrial Automation: Photoelectric switches, induction switches, and infrared luminescent micro light barriers.
- 💾 Legacy Electronics: Floppy disk drivers and other legacy office automation equipment.
📊 Key Technical Specifications
🔍 The XL-3528PDC functions as an NPN phototransistor with peak sensitivity at 940nm, making it highly effective for standard IR sources. Performance is rated at $T_a=25^\circ\text{C}$.
| Parameter | Symbol | Min | Typ. | Max | Unit | Test Condition |
|---|---|---|---|---|---|---|
| Breakdown Voltage (C-E) | $BV_{CEO}$ | 30 | --- | 100 | V | $I_c=100\mu A$ |
| Collector Photo Current | $I_{CE}$ | 300 | --- | 600 | $\mu A$ | $V_{CE}=5V$, $E_c=1mW/cm^2$ |
| Collector Dark Current | $I_{CEO}$ | --- | --- | 100 | nA | $V_{CE}=5V$, $E_e=0$ |
| Peak Wavelength | $\lambda_p$ | --- | 940 | --- | nm | --- |
| Spectral Bandwidth | $\lambda$ | 730 | --- | 1000 | nm | --- |
| Saturation Voltage | $V_{CE(sat)}$ | --- | --- | 6.5 | V | $I_c=2mA$ |
⚠️ Absolute Maximum Ratings & Process Limits
💥 Exceeding these limits may cause permanent device failure. Engineers must strictly observe these stress boundaries for safe operation and manufacturing feasibility.
| Parameter | Symbol | Maximum Rating | Unit | Notes |
|---|---|---|---|---|
| Collector-Emitter Voltage | $V_{CEO}$ | 30 | V | Reverse voltage limit |
| Emitter-Collector Voltage | $V_{ECO}$ | 5 | V | Forward bias limit |
| Operating Temp. | $T_{opr}$ | -40 ~ +85 | °C | Ambient range |
| Storage Temp. | $T_{stg}$ | -40 ~ +85 | °C | Non-operating range |
| Soldering (Reflow) | $T_{sol}$ | 260 | °C | Max 6 seconds |
| Soldering (Manual) | $T_{sol}$ | 300 | °C | Max 3 seconds |
🔧 Package, Dimensions & Assembly Notes
📏 The XL-3528PDC follows the EIA standard 3528 footprint, ensuring compatibility with most modern pick-and-place machines.
- Dimensions: The outline measures 3.5mm x 2.8mm with a thickness of 1.9mm.
- Taping: Packaged in EIA standard compliant reels for SMT automatic production.
- Soldering Profile: Suitable for infrared reflow soldering. The moisture sensitivity level (MSL) is rated at Level 3. Floor life is limited if not stored in a dry environment; baking is recommended if the floor life is exceeded prior to reflow.
- Colloid: The transparent water-clear epoxy optimizes light entry for the infrared receiver die.
🚀 Sourcing & Supply Considerations
When integrating the XL-3528PDC into your BOM, consider these supply chain factors to mitigate risk and ensure yield rates:
- Photo Current Grading: The datasheet indicates a specific grading code (IC6-12) ranging from 0.3mA to 0.6mA. Verify the binning consistency if your design requires tight gain matching.
- Cross-Reference: This is a standard package type. If lead times extend, consider checking for 3528 alternatives from major suppliers, but verify the $V_{CEO}$ and spectral response curve first.
- Procurement Verification: Ensure authenticity by purchasing through franchised distributors to avoid counterfeits, which often fail the high-temperature storage tests (-40°C to +85°C).
- Sample Testing: Always validate the actual photo current in your specific optical circuit before full-scale production.
❓ FAQ
Q: What is the wavelength range for the XL-3528PDC?
A: The device has a spectral bandwidth range of 730nm to 1000nm, with peak sensitivity ($\lambda_p$) at 940nm. This makes it ideal for standard infrared LED pairing.
Q: Can this component be used for outdoor applications?
A: While it operates from -40°C to +85°C, the transparent epoxy is primarily designed for indoor use (smart appliances, smoke detectors). For outdoor use, additional UV shielding and conformal coating are recommended to prevent long-term degradation of the colloid.
Q: What is the Moisture Sensitivity Level (MSL)?
A: The XL-3528PDC is classified as MSL 3. Components must be soldered within 168 hours (1 week) of opening the vacuum-sealed bag, or they must be baked according to IPC/JEDEC standards to prevent popcorning during reflow.
Q: What is the difference between Absolute Max and Operating Ratings?
A: Absolute Max Ratings ($V_{CEO}$=30V) are stress limits that, if exceeded, cause damage. Operating Ratings ($T_{opr}$) define the functional environmental conditions (-40°C to +85°C) where specs are guaranteed.
Q: Is manual soldering safe for this component?
A: Yes, but with strict limits. The datasheet allows manual welding at 300°C for a maximum of 3 seconds. Exceeding this duration or temperature may delaminate the internal die attach or degrade the epoxy.
