7343/B1C2-A PSA/MS LED Lamp Datasheet - T-1 3/4 Package - 468nm Blue - 20mA 3.2V - English Technical Document

1. Product Overview

The 7343/B1C2-A PSA/MS is a high-brightness blue LED lamp designed for applications requiring superior luminous intensity. It utilizes an InGaN chip to produce blue light with a typical dominant wavelength of 470nm. The device is housed in a popular T-1 3/4 round package, offering a compact and versatile form factor suitable for a wide range of electronic assemblies.

Core Advantages: This LED series is engineered for reliability and robustness. Key features include a choice of various viewing angles, availability on tape and reel for automated assembly, and compliance with RoHS environmental standards, ensuring the product is free from hazardous substances.

Target Market: Primarily aimed at commercial and industrial signage applications. Its high brightness and color consistency make it ideal for demanding visual display systems.

2. Technical Parameter Deep Dive

2.1 Absolute Maximum Ratings

These ratings define the stress limits beyond which permanent damage to the device may occur. Operation under these conditions is not guaranteed.

• Reverse Voltage (VR): 5 V - Exceeding this voltage in reverse bias can cause junction breakdown.
• Continuous Forward Current (IF): 30 mA - The maximum DC current for reliable long-term operation.
• Peak Forward Current (IFP): 100 mA - Permissible only under pulsed conditions (duty cycle 1/10, 1kHz) to handle transient surges.
• Power Dissipation (Pd): 110 mW - The maximum power the package can dissipate at Ta=25°C, calculated as VF * IF.
• Operating & Storage Temperature: -40°C to +85°C / -40°C to +100°C. This wide range ensures functionality in harsh environments.
• ESD (HBM): 1000 V - Indicates moderate sensitivity to electrostatic discharge; proper handling procedures are necessary.
• Soldering Temperature (Tsol): 260°C for 5 seconds - Defines the reflow soldering profile tolerance.

2.2 Electro-Optical Characteristics (Ta=25°C)

These parameters are measured under standard test conditions (IF=20mA) and define the device's performance.

• Luminous Intensity (Iv): 2850 - 7150 mcd (millicandela). This wide range is managed through a binning system (see Section 3). The high minimum value indicates a bright output.
• Viewing Angle (2θ1/2): 23 degrees (typical). This is a relatively narrow beam angle, concentrating light output for directed illumination.
• Peak Wavelength (λp): 468 nm (typical). The wavelength at which the spectral emission is strongest.
• Dominant Wavelength (λd): 465 - 475 nm. The wavelength perceived by the human eye, also managed through binning.
• Spectral Bandwidth (Δλ): 25 nm (typical). Defines the color purity; a smaller bandwidth indicates a more monochromatic color.
• Forward Voltage (VF): 2.8 - 3.6 V at 20mA. The voltage drop across the LED when operating, crucial for driver design.
• Reverse Current (IR): 50 μA max at VR=5V. A measure of the junction's leakage in the off-state.

3. Binning System Explanation

To ensure color and brightness consistency in production, LEDs are sorted into performance bins.

3.1 Radiometric Intensity Binning

LEDs are categorized into four bins (P, Q, R, S) based on measured luminous intensity at 20mA. For example, Bin S offers the highest output (5650-7150 mcd). Designers must account for a ±10% measurement tolerance.

3.2 Dominant Wavelength Binning

Two wavelength bins (1 and 2) ensure color uniformity. Bin 1 covers 465-470nm, and Bin 2 covers 470-475nm, with a ±1.0nm measurement tolerance.

3.3 Forward Voltage Binning

Four voltage groups (0, 1, 2, 3) from 2.8V to 3.6V help in designing efficient current-limiting circuits and predicting power consumption, with a ±0.1V tolerance.

4. Performance Curve Analysis

The datasheet provides several characteristic curves essential for understanding device behavior under non-standard conditions.

4.1 Relative Intensity vs. Wavelength

This curve shows a sharp peak around 468nm, confirming the blue color emission with a typical bandwidth of 25nm. There is minimal emission in other spectral regions.

4.2 Directivity Pattern

The polar diagram illustrates the 23-degree viewing angle, showing how light intensity decreases as the angle from the central axis increases. This is critical for optical design in signage.

4.3 Forward Current vs. Forward Voltage (IV Curve)

The curve demonstrates the exponential relationship typical of a diode. The forward voltage increases logarithmically with current. At the typical operating point of 20mA, VF is approximately 3.2V.

4.4 Relative Intensity vs. Forward Current

Light output is nearly linear with current up to the maximum rating. However, driving the LED beyond its specified current leads to efficiency droop and accelerated degradation.

4.5 Thermal Characteristics

Relative Intensity vs. Ambient Temperature: Luminous output decreases as ambient temperature rises due to increased non-radiative recombination within the semiconductor. Effective thermal management is vital for maintaining brightness.

Forward Current vs. Ambient Temperature: For a constant voltage drive, the forward current would increase with temperature due to a decrease in VF. This highlights the importance of constant current drivers for stable operation.

5. Mechanical & Package Information

5.1 Package Dimension Drawing

The mechanical drawing specifies the T-1 3/4 package dimensions. Key measurements include the overall diameter, lead spacing, and epoxy lens geometry. All dimensions are in millimeters with a standard tolerance of ±0.25mm unless otherwise noted. The maximum protrusion of resin under the flange is 1.5mm.

5.2 Polarity Identification & Lead Frame

The cathode is typically identified by a flat spot on the lens, a shorter lead, or other marking as per the drawing. Correct polarity must be observed during installation to prevent reverse bias damage.

6. Soldering & Assembly Guidelines

6.1 Lead Forming

• Bending must occur at least 3mm from the epoxy bulb base to prevent stress cracks.
• Form leads before soldering.
• Avoid applying stress to the package; misaligned PCB holes can induce stress and degrade performance.
• Cut leads at room temperature.

6.2 Storage Conditions

• Recommended storage: ≤ 30°C and ≤ 70% Relative Humidity.
• Shelf life after shipping: 3 months under these conditions.
• For longer storage (up to 1 year), use a sealed container with nitrogen and desiccant.
• Avoid rapid temperature changes in humid environments to prevent condensation.

6.3 Soldering Recommendations

Hand Soldering: Iron tip temperature ≤ 300°C (30W max), soldering time ≤ 3 seconds, maintain ≥ 3mm distance from the epoxy bulb.

Wave/Dip Soldering: Preheat ≤ 100°C for ≤ 60 sec, solder bath at ≤ 260°C for ≤ 5 sec, maintain ≥ 3mm distance from the bulb.

General Rules: Avoid stress on leads during high-temperature processes. Do not solder (dip or hand) more than once. Allow the LED to cool naturally after soldering.

7. Packaging & Ordering Information

7.1 Packing Specification

LEDs are packed in anti-static bags to prevent ESD damage. The packing hierarchy is: 200-500 pcs per bag -> 5 bags per inner carton -> 10 inner cartons per master (outside) carton.

7.2 Label Explanation

Labels on bags/cartons include: CPN (Customer Product Number), P/N (Product Number), QTY (Quantity), CAT (Intensity & Voltage Bin), HUE (Wavelength Bin), REF (Reference), and LOT No. (Traceability code).

7.3 Production Designation / Part Numbering

The part number 7343/B1C2-A PSA/MS follows a structured format where elements denote the series, color (Blue), luminous intensity bin, voltage group, viewing angle, and lens type. This allows precise ordering of the desired performance characteristics.

8. Application Suggestions

8.1 Typical Application Scenarios

• Color Graphic Signs & Message Boards: The high brightness and saturated blue color make it excellent for full-color RGB displays or monochrome blue messaging.
• Variable Message Signs (VMS): Used on highways or public information displays, where reliability and visibility under various lighting conditions are critical.
• Commercial Outdoor Advertising: Suitable for large-format displays where individual pixel brightness contributes to overall image clarity and impact.

8.2 Design Considerations

• Current Driving: Always use a constant current driver set to ≤ 30mA DC to ensure stable light output and long lifetime. Consider derating for high ambient temperatures.
• Thermal Management: While the package has limited thermal path, ensuring good airflow or heatsinking on the PCB can mitigate temperature rise, preserving intensity and longevity.
• Optical Design: The 23-degree viewing angle provides directed light. For wider illumination, secondary optics (diffusers, lenses) may be required.
• ESD Protection: Implement ESD protection on PCB lines connected to the LED, especially in environments prone to static discharge.

9. Technical Comparison & Differentiation

Compared to generic 5mm blue LEDs, the 7343/B1C2-A offers significantly higher luminous intensity (thousands of mcd vs. hundreds), making it suitable for applications where visibility is paramount. Its structured binning system provides better color and brightness consistency for large-scale displays compared to unbinned or loosely binned alternatives. The robust package and detailed handling specifications indicate a product designed for industrial reliability rather than hobbyist use.

10. Frequently Asked Questions (Based on Technical Parameters)

Q1: Can I drive this LED at 30mA continuously?
A: Yes, 30mA is the Absolute Maximum Rating for continuous forward current. For optimal lifetime and reliability, operating at or below the typical 20mA test condition is recommended, especially in high-temperature environments.

Q2: What is the difference between Peak Wavelength and Dominant Wavelength?
A: Peak Wavelength (λp) is the physical peak of the spectral output curve (468nm). Dominant Wavelength (λd) is the single wavelength that would match the perceived color (470nm typical). Designers should use Dominant Wavelength for color specification.

Q3: How do I select the right bin for my application?
A: For uniform appearance in an array, specify tight bins for Dominant Wavelength (e.g., Bin 1 only). For maximum brightness, specify the highest Intensity Bin (S). Your supplier can provide binned parts per the datasheet ranges.

Q4: Why is the soldering distance (3mm from bulb) so important?
A: The epoxy lens and the internal wire bonds are sensitive to heat. Excessive heat during soldering can crack the epoxy, deform the lens, or break the bonds, leading to immediate or latent failure.

11. Practical Design Case Study

Scenario: Designing a high-brightness blue status indicator for an outdoor telecommunications cabinet.
Selection: The 7343/B1C2-A in Bin S (highest intensity) and Bin 1 (consistent blue) is chosen for maximum visibility under sunlight.
Circuit Design: A simple constant current circuit using a linear regulator is designed for 20mA drive from a 12V supply, calculating a series resistor based on a typical VF of 3.2V. A transient voltage suppressor is added for surge protection.
Layout: The PCB footprint matches the datasheet drawing. A thermal relief pattern connects the cathode pad to a small copper pour for minor heat dissipation. The LED is placed ≥ 3mm from other components to allow for hand soldering access.
Result: A reliable, bright indicator that meets the environmental and visibility requirements.

12. Technology Principle Introduction

This LED is based on an Indium Gallium Nitride (InGaN) semiconductor chip. When a forward voltage is applied, electrons and holes are injected into the active region where they recombine, releasing energy in the form of photons (light). The specific composition of the InGaN alloy determines the bandgap energy, which in turn defines the wavelength of the emitted light—in this case, blue (~468-470nm). The epoxy package serves to protect the chip, act as a primary lens to shape the light output, and provide mechanical support for the leads.

13. Industry Trends & Developments

The LED industry continues to focus on increasing luminous efficacy (lumens per watt), improving color rendering, and reducing costs. For indicator and signage lamps like the 7343 series, trends include further miniaturization while maintaining or increasing output, enhanced reliability for 24/7 operation, and the development of even tighter binning tolerances to enable seamless large-area displays. The underlying InGaN technology is also the foundation for white LEDs (via phosphor conversion) and high-power lighting applications, driving continuous process improvements that benefit all LED product categories.