ELS-2326SURWA/S530-A3 Seven Segment Display Datasheet - 57.0mm Digit Height - 2.0V Forward Voltage - Brilliant Red - English Technical Document

1. Product Overview

The ELS-2326SURWA/S530-A3 is a through-hole mounted, seven-segment alphanumeric display designed for applications requiring clear, reliable numeric readouts in various lighting conditions. This device belongs to a family of industrial-standard components known for their durability and consistent performance.

1.1 Core Features and Advantages

The primary advantages of this display module stem from its design and material selection. It features a standard industrial footprint, ensuring compatibility with existing PCB layouts and sockets designed for similar components. A key benefit is its low power consumption, which makes it suitable for battery-powered or energy-sensitive applications. The device is constructed using Pb-free materials and is fully compliant with RoHS directives, addressing modern environmental and regulatory requirements. The segments are white, set against a gray surface, which provides a high contrast ratio for improved readability.

1.2 Target Market and Positioning

This display is positioned for use in cost-effective, reliability-focused applications where clear numeric indication is paramount. Its design prioritizes long-term performance in standard operating environments rather than extreme conditions requiring specialized components.

2. In-Depth Technical Parameter Analysis

The performance of the ELS-2326SURWA/S530-A3 is defined by a set of electrical, optical, and thermal parameters that designers must consider for successful implementation.

2.1 Absolute Maximum Ratings

These ratings define the stress limits beyond which permanent damage to the device may occur. They are not intended for normal operation.

• Reverse Voltage (V_R): 5 V. Exceeding this voltage in reverse bias can cause junction breakdown.
• Continuous Forward Current (I_F): 25 mA. This is the maximum DC current that can be applied continuously to each segment.
• Peak Forward Current (I_FP): 60 mA. This is permissible only under pulsed conditions (duty cycle ≤ 10%, frequency ≤ 1 kHz) and must not be used for DC operation.
• Power Dissipation (P_d): 60 mW. The maximum power that can be dissipated as heat, calculated as Forward Voltage (V_F) × Forward Current (I_F).
• Operating Temperature (T_opr): -40°C to +85°C. The ambient temperature range over which the device is specified to operate correctly.
• Storage Temperature (T_stg): -40°C to +100°C.
• Soldering Temperature (T_sol): 260°C for a maximum of 5 seconds. This is critical for wave or hand soldering processes to prevent thermal damage to the epoxy resin and internal bonds.

2.2 Electro-Optical Characteristics

Measured at a standard junction temperature (T_a = 25°C), these parameters define the device's light output and electrical behavior under normal operating conditions.

• Luminous Intensity (I_v): 15 mcd (Min), 34 mcd (Typ) at I_F = 10 mA. This is the average light output per segment. A ±10% tolerance is applied to this value, meaning devices are binned or categorized based on measured intensity.
• Peak Wavelength (λ_p): 632 nm (Typ). The wavelength at which the spectral emission is strongest. This is a key parameter for the perceived color (brilliant red).
• Dominant Wavelength (λ_d): 624 nm (Typ). The single wavelength that best matches the perceived color of the light, which may differ slightly from the peak wavelength.
• Spectral Bandwidth (Δλ): 20 nm (Typ). The range of wavelengths emitted, measured at half the peak intensity (Full Width at Half Maximum). A narrower bandwidth indicates a more spectrally pure color.
• Forward Voltage (V_F): 2.0 V (Typ), 2.4 V (Max) at I_F = 20 mA. This is the voltage drop across the LED when operating. The driver circuit must be designed to provide sufficient voltage. A ±0.1V tolerance is specified.
• Reverse Current (I_R): 100 µA (Max) at V_R = 5 V. This is the small leakage current that flows when the device is reverse-biased within its maximum rating.

3. Binning and Categorization System

The datasheet indicates that devices are \"Categorized for luminous intensity.\" This refers to a common practice in LED manufacturing known as \"binning.\"

3.1 Luminous Intensity Binning

Due to inherent variations in the semiconductor epitaxial growth and manufacturing process, the light output of LEDs can vary. To ensure consistency for the end-user, manufacturers test and sort (bin) LEDs into groups based on their measured luminous intensity. The ELS-2326SURWA/S530-A3 has a typical intensity of 34 mcd with a minimum of 15 mcd. Purchased devices will fall within a specific intensity range (bin), which should be consistent within a single production lot or order. The label explanation includes \"CAT: Luminous Intensity Rank,\" confirming this practice.

3.2 Forward Voltage Consistency

While not explicitly described as a binned parameter, the tight tolerance on forward voltage (±0.1V) suggests careful process control. Consistent V_F is important for designing simple series resistor current-limiting circuits, as it minimizes brightness variation between segments when driven from a common voltage source.

4. Performance Curve Analysis

Graphical data provides insight into how parameters change with operating conditions.

4.1 Spectrum Distribution

The spectrum curve shows the relative intensity of light emitted across different wavelengths. For this AlGaInP-based device, the curve will be centered around 632 nm (peak) with a typical bandwidth of 20 nm. This curve confirms the monochromatic \"brilliant red\" color without significant emission in other color bands.

4.2 Forward Current vs. Forward Voltage (I-V Curve)

This curve illustrates the non-linear relationship between current and voltage in a semiconductor diode. For the LED, a small increase in voltage beyond the turn-on threshold (~1.8V) causes a large, exponential increase in current. This is why LEDs must be driven with a current-limited source (e.g., a constant current driver or a series resistor), not a constant voltage source, to prevent thermal runaway and destruction.

4.3 Forward Current Derating Curve

This is one of the most critical graphs for reliable design. It shows how the maximum allowable continuous forward current (I_F) must be reduced as the ambient temperature increases. At 25°C, the full 25 mA is allowed. As temperature rises towards the maximum operating temperature of 85°C, the permissible current decreases significantly. This derating is necessary because the LED's internal junction temperature rises with both ambient temperature and self-heating from current flow. Exceeding the safe junction temperature degrades light output and drastically shortens lifespan. Designers must use this curve to select an appropriate operating current for their application's worst-case ambient temperature.

5. Mechanical and Package Information

5.1 Physical Dimensions

The device has a digit height of 57.0 mm (2.24 inches), which classifies it as a large-format display suitable for viewing from a distance. The package dimension drawing provides detailed measurements for the overall display body, the spacing and size of the through-hole pins, and the segment layout. A general tolerance of ±0.25 mm applies unless otherwise specified. The drawing is essential for creating the PCB footprint, ensuring proper fit, and defining the keep-out area on the board.

5.2 Pinout and Internal Circuit Diagram

The internal circuit diagram shows the electrical connection of the individual segments (a through g) and the common connection. This display uses a common-anode configuration, meaning the anodes (positive sides) of all LED segments are connected together internally to a common pin (or set of pins). The cathodes (negative sides) of each segment are brought out to individual pins. To illuminate a segment, the common anode pin is connected to a positive voltage supply, and the corresponding cathode pin is pulled low (grounded) through a current-limiting resistor. The pinout diagram specifies which physical pin corresponds to each segment cathode and the common anode.

6. Soldering and Assembly Guidelines

Proper handling is required to maintain device integrity and performance.

6.1 Soldering Parameters

The absolute maximum rating specifies a soldering temperature of 260°C for a maximum of 5 seconds. This applies to the lead/wire temperature during wave soldering or manual soldering. For reflow soldering, a standard lead-free profile with a peak temperature not exceeding 260°C should be used. Prolonged exposure to high temperature can damage the internal wire bonds, degrade the epoxy package, or cause delamination.

6.2 Electrostatic Discharge (ESD) Protection

The datasheet contains a strong warning about ESD sensitivity. The AlGaInP semiconductor die is vulnerable to damage from static electricity, which may cause immediate failure or latent defects that reduce long-term reliability. Mandatory precautions include: operators wearing grounded wrist straps; using ESD-safe workstations, mats, and tools; ensuring all equipment is properly grounded; and storing/transporting devices in conductive or anti-static packaging. Ionizers can be used to neutralize charge on non-conductive materials in the work area.

6.3 Storage Conditions

Devices should be stored within the specified storage temperature range of -40°C to +100°C, in a dry environment to prevent moisture absorption, and in their original ESD-protective packaging until ready for use.

7. Packaging and Ordering Information

7.1 Packing Specification

The device follows a specific packing process: 10 pieces are packed in a tube for mechanical protection and handling. 10 tubes are then placed into a box. Finally, 4 boxes are packed into a master shipping carton. This hierarchical packing (10 PCS/Tube → 10 Tubes/Box → 4 Boxes/Carton) is common for through-hole components and aids in inventory management and automated assembly.

7.2 Label Explanation

Labels on the packaging contain several codes: CPN (Customer's Part Number), P/N (Manufacturer's Part Number: ELS-2326SURWA/S530-A3), QTY (Quantity), CAT (Luminous Intensity Category/Rank), and LOT No (Traceable manufacturing lot number). The \"CAT\" code is crucial for ensuring brightness consistency across a production run.

8. Application Notes and Design Considerations

8.1 Typical Application Scenarios

The datasheet suggests three primary applications: Home Appliances (e.g., oven timers, washing machine displays), Instrument Panels (for industrial equipment, test gear, or automotive aftermarket), and General Digital Readout Displays. Its large size and good contrast make it suitable for applications where the display needs to be read from several feet away or in reasonably bright ambient light.

8.2 Driver Circuit Design

Designing the driver circuit requires several key calculations. First, determine the operating current (I_F) based on the required brightness and the ambient temperature using the derating curve. A typical value might be 10-20 mA. For a simple series resistor design with a common-anode display connected to a supply voltage V_CC, the resistor value for each segment is: R = (V_CC - V_F) / I_F. Using the typical V_F of 2.0V and a 5V supply with I_F=15mA gives R = (5 - 2.0) / 0.015 = 200 Ω. The resistor power rating should be at least I_F² × R = (0.015)² × 200 = 0.045W, so a standard 1/8W (0.125W) resistor is sufficient. For multiplexing multiple digits, dedicated driver ICs (like 74HC595 shift registers or MAX7219 display drivers) are commonly used to control the segment cathodes and digit anodes, significantly reducing the number of required microcontroller I/O pins.

8.3 Thermal Management

While not a high-power device, thermal considerations are still important for longevity. Ensure adequate spacing on the PCB to allow for some air circulation. Avoid placing the display near other significant heat sources. Adhering to the current derating curve is the primary method of thermal management. The wide operating temperature range (-40°C to +85°C) indicates robustness for most indoor and many outdoor environments.

9. Technical Comparison and Differentiation

The ELS-2326SURWA/S530-A3 is differentiated by its specific combination of attributes: a large 57.0mm digit height, through-hole mounting, brilliant red AlGaInP emission, and a common-anode configuration. Compared to smaller displays (e.g., 14.2mm or 20mm), it offers superior visibility at a distance. Compared to surface-mount device (SMD) displays, through-hole versions like this one are often perceived as more robust for high-vibration environments or applications requiring manual repair, and they are typically easier to prototype with. The AlGaInP material system offers high efficiency and good color purity in the red/orange/amber spectrum compared to older technologies.

10. Frequently Asked Questions (Based on Technical Parameters)

Q: Can I drive this display directly from a 5V microcontroller pin?
A: No. A microcontroller pin cannot source or sink enough current (typically 20-40mA max per pin, with a total package limit) to drive multiple segments brightly. More importantly, an LED must have its current limited. Connecting it directly to a voltage source without a series resistor would attempt to draw excessive current, damaging both the LED and possibly the microcontroller pin. Always use a series current-limiting resistor or a dedicated constant-current driver.

Q: Why is my display dim when I operate it at 85°C, even though I'm using the same current as at room temperature?
A: LED luminous efficacy (light output per unit of electrical input) decreases as junction temperature increases. This is a fundamental property of semiconductors. Furthermore, the derating curve requires you to reduce the operating current at high ambient temperatures to prevent overheating. Both effects contribute to reduced brightness at high temperature.

Q: What does \"Pb free and RoHS compliant\" mean for my design?
A: It means the device does not contain lead (Pb) or other restricted hazardous substances as defined by the RoHS (Restriction of Hazardous Substances) directive. This is a legal requirement for selling electronic products in many regions, including the European Union. It also affects your soldering process, requiring the use of lead-free solder with a higher melting point, which is why the 260°C soldering rating is important.

Q: The forward voltage is 2.0V typical. Can I power it from a 3.3V system?
A: Yes, absolutely. With a 3.3V supply (V_CC), the series resistor value would be recalculated. For I_F=15mA: R = (3.3 - 2.0) / 0.015 ≈ 87 Ω. Ensure your driver circuit (microcontroller, driver IC) can handle the segment current when pulling the cathode low.

11. Design and Usage Case Study

Scenario: Designing a simple digital timer for a laboratory incubator.
The display needs to be readable from across the room in ambient lab light. The ELS-2326SURWA/S530-A3's 57.0mm height is chosen for visibility. The incubator has an internal microcontroller running at 5V. A common-anode configuration is selected for simplicity. The design uses a single 74HC595 shift register to control the 7 segment cathodes, and a transistor array (e.g., ULN2003) to sink current for the common anodes of 4 digits, allowing multiplexing. The operating current is set to 12 mA per segment to ensure good brightness while staying well within the 25mA limit and allowing headroom for temperature derating inside the warm incubator enclosure (max ~40°C). Series resistors of 220 Ω are used ((5V - 2.0V)/0.012A ≈ 250Ω; 220Ω is the nearest standard value, resulting in I_F ≈ 13.6mA). The PCB layout includes the exact footprint from the datasheet, and during assembly, technicians use ESD straps and a temperature-controlled soldering iron set to 350°C with quick, sub-3-second joints per pin.

12. Operational Principle

A seven-segment display is an assembly of seven light-emitting diode (LED) bars arranged in a figure-eight pattern. Each bar is an independent LED. By selectively illuminating specific combinations of these seven segments, all decimal digits (0-9) and some letters can be formed. In a common-anode display like this one, all the anodes (positive terminals) of the segment LEDs are connected together to a common node. The cathodes (negative terminals) are separate. To light a segment, a positive voltage is applied to the common anode, and the cathode of the desired segment is connected to a lower voltage (usually ground) through a current-limiting circuit. The AlGaInP (Aluminum Gallium Indium Phosphide) semiconductor material used in this device is a direct bandgap compound specifically engineered to emit light in the red to amber region of the visible spectrum when electrons recombine with holes across the bandgap, a process called electroluminescence.

13. Technology Trends

The market for discrete seven-segment displays has been largely stable, with through-hole types like this one serving legacy designs, repair markets, and applications where robustness is valued. The broader trend in display technology is towards surface-mount devices (SMDs) for automated assembly, higher-density multi-digit modules, and the integration of controllers and drivers into the display package. There is also a trend towards wider color gamuts and the use of advanced phosphors in white LEDs, but for monochromatic red indicators, AlGaInP remains the dominant high-efficiency technology. The principles of current drive, thermal management, and ESD protection covered in this datasheet are fundamental and apply universally across LED technologies, from this discrete display to modern high-power lighting LEDs.