ELD-512SURWB/S530-A3 LED Display Datasheet - 14.22mm Digit Height - 2.4V Forward Voltage - 25mA Forward Current - Brilliant Red Color

1. Product Overview

The ELD-512SURWB/S530-A3 is a high-reliability, seven-segment alphanumeric display designed for through-hole mounting. It features a standard industrial size with a digit height of 14.22mm (0.56 inches), making it suitable for applications requiring clear numeric readouts. The display utilizes white segments on a black background surface, providing excellent contrast and readability even in bright ambient lighting conditions. Its construction and materials are compliant with Pb-free and RoHS environmental standards.

1.1 Core Advantages and Target Market

The primary advantages of this display include its low power consumption, standardized footprint for easy integration into existing designs, and categorization of luminous intensity for consistent performance across production batches. It is built for reliability in demanding environments. The target applications are primarily in consumer and industrial electronics, including home appliances (e.g., ovens, microwaves), various instrument panels for measurement and control systems, and general-purpose digital readout displays where clear, legible numbers are required.

2. Technical Parameter Deep-Dive

This section provides a detailed, objective analysis of the device's electrical, optical, and thermal characteristics as defined in the absolute maximum ratings and electro-optical characteristics tables.

2.1 Absolute Maximum Ratings

The device is rated for a maximum continuous forward current (I_F) of 25 mA. For pulsed operation with a duty cycle of 1/10 at 1 kHz, the peak forward current (I_FP) can reach 60 mA. The maximum reverse voltage (V_R) is limited to 5 V; exceeding this can damage the LED junctions. The total power dissipation (P_d) must not exceed 60 mW. The operational temperature range is specified from -40°C to +85°C, with a wider storage temperature range of -40°C to +100°C. The device can withstand a soldering temperature of 260°C for a maximum duration of 5 seconds, which is compatible with standard lead-free reflow and hand-soldering processes.

2.2 Electro-Optical Characteristics

Under standard test conditions (Ta=25°C, I_F=10mA), the typical luminous intensity (I_v) for a single segment is 17.6 mcd, with a minimum specified value of 7.8 mcd. The forward voltage (V_F) at 20mA is typically 2.0V, with a maximum of 2.4V. The emitted color is brilliant red, achieved using an AlGaInP (Aluminum Gallium Indium Phosphide) chip material. The peak wavelength (λ_p) is typically 632 nm, and the dominant wavelength (λ_d) is typically 624 nm, with a spectral bandwidth (Δλ) of approximately 20 nm, defining the purity and shade of the red color. The reverse current (I_R) is very low, with a maximum of 100 µA at 5V reverse bias.

2.3 Thermal Characteristics

The device's performance is temperature-dependent. The forward current must be derated as the ambient temperature increases above 25°C to prevent exceeding the maximum junction temperature and ensure long-term reliability. The provided forward current derating curve visually defines the maximum allowable continuous current at any given operating temperature within the specified range.

3. Binning System Explanation

The datasheet indicates that the devices are categorized (binned) for luminous intensity. This means during manufacturing, LEDs are tested and sorted into groups based on their measured light output at a standard current (e.g., 10mA). This ensures consistency in brightness for end-users, especially important when multiple displays are used in a single product. The tolerance for luminous intensity is specified as ±10%. Similarly, the forward voltage has a tolerance of ±0.1V around the typical value, which aids in designing stable driver circuits.

4. Performance Curve Analysis

4.1 Spectrum Distribution

The spectral distribution curve shows the relative intensity of light emitted across different wavelengths. For this AlGaInP-based red LED, the curve will be centered around the 624-632 nm range with the specified 20 nm bandwidth. This curve is important for applications where color purity or specific wavelength matching is critical.

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

This fundamental curve illustrates the relationship between the voltage applied across the LED and the resulting current flow. It is non-linear. The typical V_F of 2.0V at 20mA is a key operating point from this curve. Understanding this relationship is essential for designing appropriate current-limiting circuitry, as LEDs are current-driven devices.

4.3 Forward Current Derating Curve

This crucial graph plots the maximum allowable continuous forward current against the ambient temperature. As temperature rises, the maximum safe current decreases linearly. Adhering to this derating curve is vital for preventing thermal runaway and ensuring the device operates within its safe operating area (SOA), thereby maximizing its operational lifespan.

5. Mechanical and Package Information

The device is a through-hole component with a standard 14.22mm digit height package. The detailed package dimension drawing provides all critical mechanical measurements, including overall height, width, digit segment dimensions, and lead (pin) spacing and diameter. Tolerances for unspecified dimensions are ±0.25mm. The internal circuit diagram shows the common-anode configuration of the seven segments and the decimal point, which is essential for correctly designing the multiplexing or direct drive circuitry. The pinout identifies which pin corresponds to each segment (a-g) and the common anode.

6. Soldering and Assembly Guidelines

The absolute maximum rating for soldering temperature is 260°C for a duration not exceeding 5 seconds. This parameter must be strictly observed during wave soldering or hand-soldering processes to prevent damage to the internal LED chips and the epoxy resin package. Standard ESD (Electrostatic Discharge) precautions must be followed during handling and assembly, as the LED dice are sensitive to static electricity. This includes the use of grounded wrist straps, ESD-safe workstations, and conductive floor mats. The LEDs must always be operated under forward bias conditions.

7. Packaging and Ordering Information

The standard packing process is: 20 pieces per tube, 63 tubes per box, and 4 boxes per master carton. The label on the packaging contains several key fields for traceability and identification: CPN (Customer's Product Number), P/N (Product Number), QTY (Packing Quantity), CAT (Luminous Intensity Rank/Category), and LOT No. (Lot Number). Understanding this labeling is important for inventory control and ensuring the correct component version is used in production.

8. Application Recommendations

8.1 Typical Application Circuits

As a common-anode display, each segment cathode is driven independently, typically via a current-limiting resistor and a transistor or a dedicated LED driver IC capable of sinking the required current. The common anode pin is connected to the positive supply voltage. Multiplexing several digits is a common technique to reduce the number of required driver pins on a microcontroller.

8.2 Design Considerations and Warnings

Current Limiting: A series resistor is mandatory for each segment to set the forward current to the desired value (e.g., 10-20 mA), calculated based on the supply voltage and the LED's forward voltage. Reverse Voltage Protection: The circuit must be designed to prevent the application of reverse voltage exceeding 5V, as this can cause irreversible damage. If the driving circuit could expose the LED to reverse voltage when off, a protection diode in parallel with the LED (reverse-biased during normal operation) may be necessary. Thermal Management: Ensure the operating current is derated according to the ambient temperature. In high-temperature environments, consider reducing the drive current or improving ventilation.

9. Technical Comparison and Differentiation

Compared to older technologies or smaller displays, the ELD-512SURWB/S530-A3 offers a balance of size (0.56\"), brightness, and reliability. Its key differentiators include the use of efficient AlGaInP semiconductor material for bright red emission, a white-on-black design for high contrast, and compliance with modern environmental standards (Pb-free, RoHS). The through-hole design offers mechanical robustness and ease of prototyping compared to surface-mount alternatives, though it requires more board space.

10. Frequently Asked Questions (FAQs)

Q: What is the purpose of the luminous intensity categorization (CAT)?
A: It groups LEDs with similar brightness levels. This ensures uniform appearance when multiple displays are used side-by-side in a product, avoiding bright/dim mismatches.

Q: Can I drive this display directly from a 5V microcontroller pin?
A: No. You must use a current-limiting resistor. For a 5V supply, a typical V_F of 2.0V, and a desired I_F of 20mA, the resistor value would be R = (5V - 2.0V) / 0.020A = 150 Ω. Also, ensure the MCU pin can sink the required segment current.

Q: What does \"common anode\" mean?
A: It means the anodes (positive sides) of all LED segments are connected together to one common pin. To light a segment, you connect the common anode to Vcc and drive the corresponding cathode pin LOW (to ground through a resistor).

Q: Is a heat sink required?
A> For continuous operation at the maximum rated current (25mA) near the upper temperature limit, careful board layout for heat dissipation is advised. For most applications at moderate currents and temperatures, no separate heat sink is needed.

11. Practical Design and Usage Examples

Example 1: Simple 4-Digit Voltmeter Display. Four ELD-512SURWB displays can be multiplexed to show a voltage reading from 0.000 to 19.99V. A microcontroller would sequentially enable each digit's common anode via a PNP transistor and output the correct 7-segment pattern for that digit on the shared cathode lines, with appropriate current-limiting resistors on each cathode line. Refresh rate must be high enough (>60Hz) to avoid flicker.

Example 2: Industrial Timer/Countdown Display. Used on a control panel, the display's high contrast ensures readability in a well-lit factory environment. Its wide operating temperature range (-40°C to +85°C) makes it suitable for non-climate-controlled spaces. The driver circuit would be designed to operate at a conservative 15mA per segment to enhance long-term reliability and minimize heat generation.

12. Operating Principle Introduction

A seven-segment LED display is an assembly of multiple Light Emitting Diodes (LEDs) arranged in a figure-eight pattern. Each segment (labeled a through g) is an individual LED. When forward-biased—meaning a positive voltage is applied to the anode relative to the cathode—electrons and holes recombine within the semiconductor's active region (the AlGaInP chip in this case), releasing energy in the form of photons (light). The specific material composition (AlGaInP) determines the wavelength (color) of the emitted light, which is in the brilliant red spectrum for this device. By selectively illuminating different combinations of these seven segments, all decimal digits (0-9) and some letters can be formed.

13. Technology Trends and Context

While through-hole displays like this one remain popular for robustness and ease of use in certain applications, the overall trend in electronics is toward miniaturization and surface-mount technology (SMT). SMT displays offer smaller footprints, lower profile, and are better suited for automated pick-and-place assembly. However, through-hole components are still valued in prototyping, educational settings, industrial equipment where vibration resistance is key, and for applications where manual soldering or repair is anticipated. The underlying LED technology, AlGaInP for red/orange/yellow and InGaN for blue/green/white, continues to improve in efficiency (more light per watt) and reliability. Future displays may integrate more intelligence, such as built-in drivers or communication interfaces (e.g., I2C), simplifying the design for the end engineer.