7.62mm White Seven Segment Display Datasheet - 0.3" Digit Height - 2.4V Forward Voltage - 25mA Forward Current - English Technical Document

1. Product Overview

This document details the specifications for a 7.62mm (0.3 inch) digit height, seven-segment alphanumeric display. The device is designed for through-hole mounting (THT) and features white light-emitting segments against a gray background surface. This combination provides high contrast and excellent readability even in bright ambient lighting conditions, making it suitable for various indicator and readout applications. The product is categorized for luminous intensity and is compliant with Pb-free and RoHS environmental standards.

1.1 Core Advantages and Target Market

The primary advantages of this display include its industrial standard footprint, which ensures compatibility with existing PCB layouts and sockets, and its low power consumption characteristics. The device is built for reliability and longevity. Its primary target markets include consumer home appliances, industrial and automotive instrument panels, and general-purpose digital readout displays where clear, monochrome numeric or limited alphanumeric information needs to be presented.

2. Technical Parameter Deep-Dive

The performance of the display is defined by a set of absolute maximum ratings and standard electro-optical characteristics measured at an ambient temperature (Ta) of 25°C.

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. They should not be exceeded under any operating conditions.

• Reverse Voltage (V_R): 5 V - The maximum voltage that can be applied in the reverse direction across the LED segment.
• Forward Current (I_F): 25 mA - The maximum continuous DC current allowed through a single segment.
• Peak Forward Current (I_FP): 60 mA - The maximum pulsed current, permissible only under a duty cycle of 1/10 at 1 kHz frequency.
• Power Dissipation (P_d): 60 mW - The maximum power that can be dissipated by a single segment.
• Operating Temperature (T_opr): -40°C to +85°C - The ambient temperature range over which the device is designed to function.
• 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 wave or hand soldering, with exposure time not exceeding 5 seconds.

2.2 Electro-Optical Characteristics

These are the typical performance parameters under specified test conditions.

• Luminous Intensity (I_v): 5.6 mcd (Min), 11.0 mcd (Typ) per segment, measured at I_F = 10 mA. The tolerance is ±10%.
• Peak Wavelength (λ_p): 632 nm (Typ) at I_F = 20 mA. This indicates the wavelength at which the emitted light intensity is highest.
• Dominant Wavelength (λ_d): 624 nm (Typ) at I_F = 20 mA. This is the wavelength perceived by the human eye, defining the color (white, in this case, based on the chip material).
• Spectrum Radiation Bandwidth (Δλ): 20 nm (Typ) at I_F = 20 mA. This defines the spectral width of the emitted light.
• Forward Voltage (V_F): 2.0 V (Typ), 2.4 V (Max) at I_F = 20 mA. The tolerance is ±0.1V. This is the voltage drop across the LED when operating.
• Reverse Current (I_R): 100 µA (Max) at V_R = 5 V.

3. Binning System Explanation

The datasheet indicates that the devices are \"Categorized for luminous intensity.\" This implies a binning system is in place.

3.1 Luminous Intensity Binning

While specific bin codes are not listed in the provided excerpt, the typical luminous intensity is 11.0 mcd with a minimum of 5.6 mcd at 10mA. Manufacturers typically group LEDs into bins based on measured luminous output to ensure consistency within a production batch. Designers should consult the manufacturer's full binning documentation to select the appropriate intensity grade for their application, ensuring uniform brightness across all digits in a multi-digit display.

4. Performance Curve Analysis

The datasheet references typical characteristic curves which are crucial for understanding device behavior under non-standard conditions.

4.1 Spectrum Distribution

The spectrum distribution curve (at Ta=25°C) would graphically show the relative luminous intensity across different wavelengths, centered around the typical peak wavelength of 632 nm. This curve helps in understanding the color purity and potential application in optical filtering scenarios.

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

This curve (at Ta=25°C) illustrates the non-linear relationship between the current flowing through the LED segment and the voltage across it. It is essential for designing the current-limiting circuitry (usually a resistor in series) to ensure stable operation at the desired brightness without exceeding the maximum forward current.

4.3 Forward Current Derating Curve

This is one of the most critical curves for reliable design. It shows how the maximum allowable continuous forward current (I_F) must be reduced as the ambient operating temperature increases above 25°C. Operating at 85°C, for example, would require a significantly lower drive current than the absolute maximum rating of 25mA to prevent overheating and accelerated degradation.

5. Mechanical and Package Information

5.1 Package Dimensions

The display follows an industry-standard 7.62mm digit height footprint for through-hole mounting. The detailed dimensioned drawing provides all critical measurements including overall height, digit size, pin spacing (pitch), and pin diameter. The default tolerance for dimensions is ±0.25mm unless otherwise specified. Precise adherence to these dimensions is necessary for proper PCB layout and mechanical fit.

5.2 Pinout and Polarity Identification

The internal circuit diagram shows the common-anode configuration of the seven segments and the decimal point (if present). The diagram identifies the pin numbers corresponding to each segment (a through g) and the common anode pin(s). Correct polarity must be observed during installation; applying reverse voltage exceeding 5V can damage the LED junctions.

6. Soldering and Assembly Guidelines

6.1 Soldering Parameters

The absolute maximum rating specifies a soldering temperature (T_sol) of 260°C for a duration not exceeding 5 seconds. This applies to wave soldering or hand soldering processes. For reflow soldering, a profile compatible with the device's plastic package must be used, typically staying within the temperature limits of the epoxy resin.

6.2 Electrostatic Discharge (ESD) Precautions

The LED dice inside the display are sensitive to electrostatic discharge. Handling precautions are strongly recommended: use grounded wrist straps and workstations, employ conductive floor mats and table mats, and utilize ionizers to neutralize charge in areas with insulating materials. Proper grounding of all equipment used in assembly is required.

6.3 Storage Conditions

The device should be stored within the specified storage temperature range of -40°C to +100°C, in a dry environment to prevent moisture absorption which could cause \"popcorning\" during soldering.

7. Packaging and Ordering Information

7.1 Packaging Specification

The standard packing format is 26 pieces per tube. These tubes are then packed into boxes, with 88 tubes per box. Finally, 4 boxes are packed into a master carton.

7.2 Label Explanation

Product labels include several key fields: Customer’s Product Number (CPN), the manufacturer's Product Number (P/N), Packing Quantity (QTY), Luminous Intensity Rank (CAT), and Lot Number (LOT No). The intensity rank (CAT) correlates to the binning mentioned earlier.

8. Application Recommendations

8.1 Typical Application Circuits

As a common-anode display, each segment cathode is driven independently, typically by a microcontroller GPIO pin or a dedicated driver IC (like a 74HC595 shift register or a MAX7219). A current-limiting resistor must be connected in series with each segment cathode. The resistor value is calculated using R = (V_supply - V_F) / I_F, where V_F and I_F are the desired operating point from the datasheet (e.g., 2.0V at 10mA). For a 5V supply, R = (5V - 2.0V) / 0.01A = 300 Ohms.

8.2 Design Considerations

• Current Limiting: Always use external current-limiting resistors. Driving LEDs directly from a microcontroller pin or voltage source will likely exceed the maximum forward current and destroy the segment.
• Multiplexing: For multi-digit displays, multiplexing is common to reduce pin count. Ensure the peak current in multiplexed operation does not exceed the I_FP rating, considering the duty cycle.
• Heat Management: Adhere to the forward current derating curve. In high ambient temperature applications, reduce drive current to maintain reliability.
• Viewing Angle: The gray background improves contrast in high-ambient-light conditions but may affect viewing angle characteristics compared to black backgrounds.

9. Technical Comparison and Differentiation

Compared to similar displays with black backgrounds, the gray surface of this model offers superior readability in brightly lit environments by reducing reflected glare. The use of AlGaInP chip material for white light (likely a phosphor-converted type) typically offers good efficiency and stability. The through-hole design provides robust mechanical connection, making it suitable for applications subject to vibration or where soldering reliability is paramount, as opposed to surface-mount devices.

10. Frequently Asked Questions (FAQ)

Q: Can I drive this display directly from a 5V microcontroller pin at 20mA?
A: No. You must use a series current-limiting resistor for each segment. A microcontroller pin's current sourcing/sinking capability and the LED's V_F must both be considered in the resistor calculation.

Q: What is the difference between Peak Wavelength and Dominant Wavelength?
A: Peak wavelength is the physical peak of the emission spectrum. Dominant wavelength is the single wavelength perceived by the human eye that matches the color of the light. For white LEDs, they often differ significantly.

Q: How do I select the correct luminous intensity bin?
A> For uniform appearance in a multi-unit product, specify the required intensity bin (CAT code) to your distributor or manufacturer. Using devices from mixed bins can result in visibly different brightness levels.

Q: Is a heat sink required?
A> For continuous operation at the maximum rated current (25mA) near the upper end of the operating temperature range, careful PCB layout for heat dissipation is advised. For typical operation at 10-20mA in moderate environments, no special heat sink is needed.

11. Practical Design Case Study

Scenario: Designing a simple 4-digit voltmeter readout for an automotive dashboard application (ambient temperature up to 70°C).
Design Steps:
1. Drive Circuit: Use a microcontroller with a 4-digit, 7-segment driver peripheral or an external driver IC like the MAX7219 for multiplexing, simplifying wiring.
2. Current Setting: Consult the derating curve. At 70°C, the maximum continuous current is lower than 25mA. Selecting a drive current of 8-10mA per segment ensures reliability and adequate brightness.
3. Resistor Calculation: Assuming a 5V supply and V_F = 2.0V at 10mA, R = (5V - 2.0V) / 0.01A = 300 Ohms. Use a 300Ω or 330Ω standard value resistor per segment cathode.
4. PCB Layout: Place the display on the top side of the PCB. Ensure the pin holes match the datasheet dimensions. Provide a slightly larger ground plane around the display area to aid in heat dissipation.

12. Operating Principle

A seven-segment display is an assembly of multiple Light Emitting Diodes (LEDs) arranged in a figure-eight pattern. Each of the seven rectangular segments (labeled a through g) is an individual LED. By selectively illuminating specific combinations of these segments, the numerals 0-9 and some letters can be formed. In a common-anode configuration like this one, all the anodes of the segment LEDs are connected together to a common positive voltage supply. Each segment is turned ON by applying a logic LOW (or ground path) to its respective cathode pin through a current-limiting resistor.

13. Technology Trends

The trend in display technology is moving towards higher density, full-color, and surface-mount devices. However, through-hole seven-segment displays like this one remain highly relevant due to their simplicity, robustness, low cost, and ease of use in prototyping, educational kits, industrial controls, and applications where extreme reliability and visibility are required. Advances in LED chip materials continue to improve efficiency (lumens per watt) and longevity, even for these classic package types. The adherence to RoHS and Pb-free standards is now a universal requirement, driven by global environmental regulations.