7.62mm 0.3-inch Seven Segment Display Datasheet - Through-hole - White Segment Gray Surface - 2.4V 25mA - English Technical Document

1. Product Overview

This document details the specifications for a 7.62mm (0.3-inch) digit height, seven-segment alphanumeric display designed for through-hole mounting. The device features white segments on a gray surface, providing high contrast for optimal readability. It is constructed using AlGaInP chip technology to emit a brilliant red color, enhanced by a white diffusion resin. The display is categorized as an industrial standard size component, emphasizing reliability and consistent performance in various lighting conditions.

1.1 Core Features and Advantages

The primary advantages of this display include its compliance with industrial size standards, ensuring compatibility with existing footprint designs. It offers low power consumption, making it suitable for battery-powered or energy-sensitive applications. The device is categorized for luminous intensity, providing designers with predictable and consistent brightness levels across production batches. Furthermore, it is manufactured to be Pb-free and RoHS compliant, adhering to modern environmental and regulatory standards for electronic components.

1.2 Target Market and Applications

This display is targeted at applications requiring clear, reliable numeric or limited alphanumeric readouts. Its primary application domains include home appliances, where it might indicate settings, timers, or status codes. It is also well-suited for instrument panels in various equipment, providing critical operational data. Furthermore, it serves as a fundamental component in general-purpose digital readout displays across industrial, commercial, and consumer electronics.

2. In-Depth Technical Parameter Analysis

The performance and limits of the display are defined by a set of absolute maximum ratings and detailed electro-optical characteristics. Understanding these parameters is crucial for reliable circuit design and ensuring long-term operational integrity.

2.1 Absolute Maximum Ratings

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

• Reverse Voltage (V_R): 5 V - The maximum voltage that can be applied in the reverse direction across the LED segments.
• Forward Current (I_F): 25 mA - The maximum continuous DC current allowed through a segment.
• Peak Forward Current (I_FP): 60 mA - The maximum pulsed current, permissible under a duty cycle of 1/10 at 1 kHz.
• Power Dissipation (P_d): 60 mW - The maximum power that can be dissipated by the device.
• Operating Temperature (T_opr): -40°C to +85°C - The ambient temperature range for normal operation.
• Storage Temperature (T_stg): -40°C to +100°C - The temperature range for non-operational storage.
• Soldering Temperature (T_sol): 260°C - The maximum temperature for soldering processes, with a time limit of 5 seconds.

2.2 Electro-Optical Characteristics

These parameters, measured at a standard temperature of 25°C, define the typical performance of the device under specified test conditions.

• Luminous Intensity (I_v): The typical value is 6.4 mcd, with a minimum of 4.0 mcd, measured per single 7-segment element at a forward current of 10 mA. A tolerance of ±10% applies to this parameter.
• Peak Wavelength (λ_p): 632 nm (typical) - The wavelength at which the spectral emission is strongest, measured at I_F=20mA.
• Dominant Wavelength (λ_d): 624 nm (typical) - The wavelength perceived by the human eye, defining the color point, measured at I_F=20mA.
• Spectrum Radiation Bandwidth (Δλ): 20 nm (typical) - The spectral width of the emitted light, measured at I_F=20mA.
• Forward Voltage (V_F): 2.0 V (typical), with a maximum of 2.4 V at I_F=20mA. A tolerance of ±0.1V is specified.
• Reverse Current (I_R): Maximum of 100 µA when a reverse voltage of 5V is applied.

3. Performance Curve Analysis

Graphical representations provide deeper insight into the device's behavior under varying conditions, which is essential for robust system design.

3.1 Spectrum Distribution

The spectrum distribution curve, measured at 25°C, shows the relative luminous intensity across different wavelengths. The curve peaks at the typical 632 nm, confirming the brilliant red emission. The 20 nm bandwidth indicates a relatively narrow spectral output, which contributes to a saturated color appearance.

3.2 Forward Current vs. Forward Voltage (IV Curve)

This curve illustrates the relationship between the current flowing through an LED segment and the voltage drop across it. It is non-linear, characteristic of a diode. Designers use this curve to select appropriate current-limiting resistors to achieve desired brightness while staying within the V_F and I_F limits. The typical V_F of 2.0V at 20mA serves as a key design point.

3.3 Forward Current Derating Curve

This critical graph shows how the maximum allowable continuous forward current must be reduced as the ambient operating temperature increases above 25°C. To ensure reliability and prevent thermal runaway, the driving current must be decreased when operating at high temperatures. This curve is fundamental for designing systems intended for use in elevated temperature environments.

4. Mechanical and Package Information

4.1 Package Dimensions

The device conforms to a standard through-hole DIP (Dual In-line Package) footprint. The dimensional drawing provides all critical measurements including overall height, digit size, pin spacing (pitch), and pin diameter. Tolerances for unspecified dimensions are ±0.25mm. The exact footprint is essential for PCB (Printed Circuit Board) layout to ensure proper fit and alignment.

4.2 Internal Circuit Diagram and Pinout

The datasheet includes an internal circuit diagram showing the common-cathode or common-anode configuration of the seven segments and the decimal point (if present). This diagram is vital for correctly connecting the display to a driver circuit (e.g., a microcontroller or decoder IC). It identifies which pin corresponds to each segment (a-g) and the common pin, preventing connection errors during assembly.

5. Soldering and Assembly Guidelines

Proper handling during assembly is crucial to maintain device integrity and performance.

• Soldering: The maximum soldering temperature is rated at 260°C, and the soldering iron contact time must not exceed 5 seconds to prevent thermal damage to the LED chips and the plastic package.
• Electrostatic Discharge (ESD) Protection: The LED dice are sensitive to ESD. Mandatory anti-static measures include using grounded wrist straps, ESD-safe footwear and workstations, conductive floor mats, and proper grounding of all equipment. Ionizers can be used to neutralize charge on insulating materials.
• Storage: Devices should be stored within the specified temperature range of -40°C to +100°C in a dry, ESD-safe environment.

6. Packaging and Ordering Information

6.1 Packaging Specifications

The components are supplied in a structured packaging process: 32 pieces are mounted on a single plate. 64 of these plates are then packed into one box. Finally, 4 boxes are combined into a master carton. This totals 8192 pieces per carton (32 x 64 x 4).

6.2 Label Explanation

Labels on the packaging contain several key identifiers: CPN (Customer's Product Number), P/N (Manufacturer's Product Number), QTY (Packing Quantity), CAT (Luminous Intensity Rank/Category), and LOT No (Traceable Lot Number). Other fields like HUE, REF, and REFERENCE may contain internal codes for color reference or volume labeling.

7. Application Design Considerations

7.1 Driver Circuit Design

Each segment is an individual LED. A current-limiting resistor must be connected in series with each segment (or with the common pin in a common-cathode/anode configuration) to set the operating current. The resistor value (R) can be calculated using Ohm's Law: R = (V_supply - V_F) / I_F. Using the typical V_F of 2.0V and a desired I_F of 10mA (for standard brightness) with a 5V supply gives R = (5V - 2.0V) / 0.01A = 300 Ω. A slightly higher value (e.g., 330 Ω) is often used for margin. For multiplexing multiple digits, the peak current per segment must be adjusted to keep the average current within the continuous rating.

7.2 Thermal Management

While the display itself has low power dissipation, the derating curve must be consulted for high-temperature applications. If the ambient temperature is expected to approach the maximum of 85°C, the forward current must be significantly reduced. Adequate spacing on the PCB and avoiding placement near other heat-generating components can help manage the local ambient temperature around the display.

7.3 Optical Considerations

The white segments on a gray background provide inherent contrast. For best readability, consider the viewing angle and distance. The typical luminous intensity value (6.4 mcd) indicates it is suitable for indoor use and well-lit environments. For direct sunlight or extremely bright ambients, a higher-brightness category or a display with a darker filter might be necessary.

8. Technical Comparison and Differentiation

This display differentiates itself through several key attributes. Its industrial standard size ensures drop-in replacement compatibility in many existing designs. The use of AlGaInP technology offers high efficiency and a saturated red color compared to older technologies. The categorization for luminous intensity provides predictable performance, which is critical for applications requiring uniform appearance across multiple units. The through-hole mounting offers mechanical robustness and ease of prototyping compared to surface-mount alternatives, though it requires manual or wave soldering processes.

9. Frequently Asked Questions (FAQ)

Q: What is the difference between peak wavelength and dominant wavelength?

A: Peak wavelength (λ_p=632nm) is the physical peak of the light emission spectrum. Dominant wavelength (λ_d=624nm) is the single wavelength that would produce the same color perception to the human eye. Dominant wavelength is more relevant for color specification.

Q: Can I drive this display directly from a microcontroller pin?

A: No. A microcontroller pin typically cannot source or sink the required 10-20mA continuously per segment and may not have the required voltage headroom. An external driver circuit (transistors, dedicated driver IC) with current-limiting resistors is always required.

Q: What does \"categorized for luminous intensity\" mean?

A: The manufacturer tests and bins the displays based on their measured brightness (mcd) at a standard current. Displays within a specific category (CAT on the label) will have very similar brightness, ensuring visual consistency when multiple displays are used together.

Q: Is a heat sink required?

A> For normal operation within the specified current and temperature limits, a separate heat sink is not required for the display package itself. The PCB acts as the primary heat dissipation path.

10. Practical Design and Usage Examples

10.1 Simple Digital Timer

A common application is a countdown or count-up timer. A microcontroller would be programmed to track time. It would output the correct segment patterns for each digit (e.g., minutes and seconds) to a driver IC like a 74HC595 shift register or a dedicated multi-digit LED driver. The driver would handle the multiplexing, turning on one digit at a time rapidly to create the illusion of all digits being on simultaneously, while keeping the total current draw manageable.

10.2 Instrument Panel Readout

In a piece of test equipment, this display could show measured values like voltage, frequency, or temperature. An analog-to-digital converter (ADC) would digitize the sensor signal. The microcontroller would scale the digital value, format it for display, and drive the segments accordingly. The gray background helps reduce glare from panel lighting, and the white segments ensure the numbers are crisp and clear.

11. Operating Principle

A seven-segment display is an assembly of seven light-emitting diodes (LEDs) arranged in a figure-eight pattern. Each LED forms one segment (labeled a through g). By selectively turning on specific combinations of these segments, the numerals 0-9 and some letters (like A, C, E, F) can be formed. In a common-cathode configuration, all the cathodes (negative sides) of the segment LEDs are connected together to a common pin. To light a segment, its individual anode (positive) pin is driven high (with a series current-limiting resistor) while the common cathode is connected to ground. A common-anode configuration is the opposite. The underlying LED chips use AlGaInP (Aluminum Gallium Indium Phosphide) semiconductor material, which emits light in the red/orange/yellow spectrum when electrons recombine with holes across the material's bandgap.

12. Technology Trends

The core technology for red LEDs, AlGaInP, is mature and highly efficient. The trend in displays is towards higher brightness, lower power consumption, and smaller pixel pitches. While through-hole displays like this one remain popular for their robustness and ease of use in certain applications, the overall industry is strongly moving towards surface-mount device (SMD) technology. SMD displays allow for automated assembly, smaller overall device profiles, and higher density on PCBs. Future developments may include integrated drivers within the display package or displays with wider viewing angles and higher contrast ratios achieved through advanced lens and filter designs. However, the fundamental simplicity, reliability, and cost-effectiveness of standard seven-segment displays ensure their continued use in a vast array of applications for the foreseeable future.