LTD-6710JD LED Display Datasheet - 0.56-inch Digit Height - AlInGaP Red - Low Current - English Technical Document

1. Product Overview

The LTD-6710JD is a dual-digit, seven-segment LED display designed for applications requiring clear numeric readouts with minimal power consumption. Its primary function is to provide a highly visible, reliable numeric display interface.

1.1 Core Advantages and Target Market

This device is built around AlInGaP (Aluminum Indium Gallium Phosphide) LED chips, which are known for their high efficiency in the red spectrum. The display features a gray face with white segments, enhancing contrast and readability. Its key advantage is its excellent performance under low current conditions, with segments matched for uniform brightness even at currents as low as 1mA per segment. This makes it ideal for battery-powered portable devices, instrumentation panels, consumer electronics, and any application where power efficiency and clear visibility are critical.

1.2 Key Features

• Digit Height: 0.56 inch (14.22 mm)
• Continuous Uniform Segments for consistent appearance
• Low Power Requirement, operable from 1mA/segment
• High Brightness & High Contrast AlInGaP red emission
• Wide Viewing Angle
• Categorized for Luminous Intensity (Binning)
• Lead-Free Package (RoHS compliant)

2. Technical Parameters: In-Depth Objective Interpretation

2.1 Absolute Maximum Ratings

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

• Power Dissipation per Segment: 70 mW
• Peak Forward Current per Segment: 100 mA (at 1/10 duty cycle, 0.1ms pulse width)
• Continuous Forward Current per Segment: 25 mA at 25°C, derating linearly at 0.33 mA/°C above 25°C.
• Operating & Storage Temperature Range: -35°C to +85°C.
• Soldering: 5 seconds at 260°C, 1/16 inch (1.6mm) below the seating plane.

2.2 Electrical & Optical Characteristics

These parameters are measured at Ta=25°C and define the device's performance under typical operating conditions.

• Average Luminous Intensity (Iv): 340 (Min), 700 (Typ) ucd at IF=1mA. This low test current highlights its efficiency.
• Peak Emission Wavelength (λp): 656 nm (Typ), indicating a deep red color.
• Dominant Wavelength (λd): 640 nm (Typ).
• Forward Voltage per Chip (VF): 2.1V (Min), 2.6V (Typ) at IF=20mA.
• Reverse Current per Segment (IR): 10 µA (Max) at VR=5V. Note this is a test condition, not an operating mode.
• Luminous Intensity Matching Ratio: 2:1 (Max) between segments under similar conditions, ensuring visual uniformity.
• Dominant Wavelength Matching Delta (Δλd): 4 nm (Max) between chips.
• Cross Talk: ≤ 2.50%, minimizing unwanted illumination of adjacent off-segments.

3. Binning System Explanation

The device is categorized (binned) for Luminous Intensity. This means units are tested and sorted into groups based on their measured light output at a standard current (1mA). Designers can select bins to ensure consistent brightness levels across multiple displays in a product. The module marking includes a \"Z\" code which identifies the specific bin.

4. Performance Curve Analysis

The datasheet references typical characteristic curves (not fully detailed in the provided excerpt). These would typically include:

• IV Curve: Relationship between Forward Current (IF) and Forward Voltage (VF). The specified VF of 2.1-2.6V at 20mA provides a key design point for current-limiting resistor calculation.
• Luminous Intensity vs. Current: Shows how light output increases with current. The high typical intensity of 700 ucd at only 1mA demonstrates exceptional efficiency.
• Temperature Characteristics: Likely shows how forward voltage and luminous intensity vary with ambient temperature. The derating specification for continuous current (0.33 mA/°C) is crucial for thermal management in high-temperature environments.

5. Mechanical & Package Information

5.1 Package Dimensions

The display has an 18-pin dual-in-line package. Critical dimensions and tolerances are provided in the drawing. Key notes include: all dimensions in mm with ±0.25mm tolerance, pin tip shift tolerance of ±0.40mm, and a recommended PCB hole diameter of 1.30mm.

5.2 Pin Connection and Polarity Identification

The LTD-6710JD is a Common Anode device. Pin 14 is the Common Anode for Digit 1, and Pin 13 is the Common Anode for Digit 2. Each segment cathode (A-G, DP) for each digit has a dedicated pin, allowing for multiplexed or static drive. The internal circuit diagram shows the anode common to all LEDs in a digit, with individual cathodes for each segment.

6. Soldering & Assembly Guidelines

6.1 Automated Soldering Profile

The recommended condition is 5 seconds at 260°C, with the solder point 1.6mm (1/16 inch) below the seating plane of the package. The temperature of the component body itself must not exceed the maximum temperature rating during assembly.

6.2 Manual Soldering

For hand soldering, the iron tip should be applied for up to 5 seconds at 350°C ±30°C, again 1.6mm below the seating plane.

7. Application Recommendations

7.1 Typical Application Scenarios

• Portable test and measurement equipment (multimeters, thermometers).
• Battery status indicators or charge level displays.
• Industrial control panel readouts.
• Consumer appliance displays (scales, timers).
• Automotive aftermarket instrumentation.

7.2 Design Considerations

• Current Limiting: Essential. Use series resistors for each segment or digit anode based on the supply voltage and desired forward current. Calculations must use the maximum VF from the datasheet to ensure current does not exceed ratings.
• Multiplexing: As a common-anode display, it is well-suited for multiplexed drive circuits to control multiple digits with fewer I/O pins. Refresh rate must be high enough to avoid flicker (typically >60Hz).
• Thermal Management: Adhere to the current derating curve above 25°C. Ensure adequate ventilation if operating at high ambient temperatures or high duty cycles.
• ESD Protection: Standard ESD precautions should be observed during handling and assembly.

8. Technical Comparison & Differentiation

The primary differentiator of the LTD-6710JD is its optimized low-current performance. While many seven-segment displays are rated for 10-20mA per segment, this device is characterized and matched at 1mA, guaranteeing excellent uniformity and brightness at very low power levels. The use of AlInGaP technology provides higher efficiency and potentially longer life compared to older GaAsP or GaP red LEDs, resulting in better brightness and color purity.

9. Frequently Asked Questions (Based on Technical Parameters)

Q: Can I drive this display with a 3.3V or 5V microcontroller?

A: Yes. With a typical VF of 2.6V at 20mA, a series resistor is required. For a 5V supply and 10mA target current: R = (5V - 2.6V) / 0.01A = 240 Ohms. For 3.3V and 5mA: R = (3.3V - 2.6V) / 0.005A = 140 Ohms. Always verify the actual current does not exceed maximum ratings.

Q: What does \"segments are matched\" mean?

A: It means the LEDs within the display are selected to have very similar electrical and optical characteristics (Iv matching ≤ 2:1, Δλd ≤ 4nm). This ensures all segments light up with nearly identical brightness and color when driven with the same current, creating a uniform, professional appearance.

Q: How do I interpret the bin code (Z) on the marking?

A: The bin code corresponds to a specific range of luminous intensity. To guarantee consistent brightness across multiple units in production, specify the required bin code when ordering. The exact intensity values for each \"Z\" code are defined in the manufacturer's internal specifications.

10. Practical Design Case

Scenario: Designing a battery-powered digital voltmeter with two digits.

Implementation: Use a microcontroller with 10 I/O pins to drive the display in a multiplexed configuration. Two pins control the digit anodes (Digits 1 & 2) via small NPN transistors or MOSFETs. The other eight pins drive the segment cathodes (A, B, C, D, E, F, G, DP) through current-limiting resistors. The firmware rapidly switches (e.g., at 100Hz) between illuminating Digit 1 and Digit 2, persisting the correct segment pattern for each. The low 1mA/segment capability allows the use of higher-value current-limiting resistors, reducing total system current draw and extending battery life significantly compared to a standard 20mA display.

11. Operating Principle Introduction

A seven-segment LED display is an assembly of light-emitting diodes arranged in a figure-eight pattern. By selectively powering different combinations of the seven segments (and optionally the decimal point), all numeric digits (0-9) and some letters can be formed. In a common-anode configuration like the LTD-6710JD, all the anodes of the LEDs for one digit are connected together to a common positive voltage pin. To illuminate a specific segment, its corresponding cathode pin is connected to a lower voltage (typically ground) through a current-limiting resistor, completing the circuit and causing the LED to emit light.

12. Technology Trends

The trend in numeric displays continues towards higher efficiency, lower power consumption, and improved readability. AlInGaP technology represents a significant step over older materials. Future developments may include even lower voltage drops, integration of driver ICs within the package for \"direct-microcontroller\" interfaces, and the adoption of new materials for different colors or broader temperature ranges. The demand for energy-efficient components in portable and IoT devices ensures the relevance of highly efficient, low-current displays like the LTD-6710JD.