LTS-360JD LED Display Datasheet - 0.36-inch Digit Height - Hyper Red Color - 2.6V Forward Voltage - English Technical Document

1. Product Overview

The LTS-360JD is a high-performance, single-digit, seven-segment display module designed for applications requiring clear, bright numeric readouts. Its primary function is to provide a highly legible digital character in a compact form factor. The core advantage of this device lies in its utilization of advanced AlInGaP (Aluminum Indium Gallium Phosphide) semiconductor technology for the LED chips, which is specifically engineered to produce a hyper red color with high luminous efficiency. This makes it suitable for a wide target market including industrial instrumentation, consumer appliances, automotive dashboards (secondary displays), test and measurement equipment, and point-of-sale terminals where reliability and visibility are paramount.

2. In-Depth Technical Parameter Analysis

This section provides a detailed, objective interpretation of the key parameters listed in the datasheet.

2.1 Photometric and Optical Characteristics

The photometric performance is central to the display's functionality. The Average Luminous Intensity (Iv) is specified from a minimum of 200 µcd to a maximum of 650 µcd at a standard test current of 1mA. This range indicates the device is categorized for brightness, allowing designers to select units with consistent output. The Dominant Wavelength (λd) is 639 nm, and the Peak Emission Wavelength (λp) is 650 nm, both measured at IF=20mA. This defines the "hyper red" color, which is a deep, saturated red. The Spectral Line Half-Width (Δλ) of 20 nm indicates a relatively narrow emission spectrum, contributing to color purity. The Luminous Intensity Matching Ratio of 2:1 maximum ensures that the brightness difference between the brightest and dimmest segment in a single unit is within an acceptable limit for uniform appearance.

2.2 Electrical Parameters

The electrical specifications define the operating limits and conditions for reliable use. The Forward Voltage per Segment (VF) has a typical value of 2.6V at IF=20mA, with a maximum of 2.6V. This is a critical parameter for designing the current-limiting resistor network. The Continuous Forward Current per Segment is rated at 25 mA maximum at 25°C, with a derating factor of 0.33 mA/°C. This means the allowable continuous current decreases as ambient temperature rises above 25°C to prevent overheating. The Peak Forward Current can be pulsed up to 90 mA under specific conditions (1/10 duty cycle, 0.1ms pulse width), which is useful for multiplexing schemes to achieve higher perceived brightness. The Reverse Voltage (VR) rating of 5V is relatively low, emphasizing the need for proper circuit design to avoid accidental reverse bias.

2.3 Thermal and Absolute Maximum Ratings

These ratings define the boundaries for safe operation and must not be exceeded. The Power Dissipation per Segment is 70 mW. The Operating and Storage Temperature Range is from -35°C to +85°C, indicating robustness for use in non-climate-controlled environments. The Solder Temperature specification (260°C for 3 seconds at 1/16 inch below the seating plane) is crucial for guiding the reflow soldering process without damaging the internal LED chips or the plastic package.

3. Binning System Explanation

The datasheet indicates that the device is categorized for luminous intensity. This implies a binning system where units are sorted and sold based on their measured light output at the standard test condition (IF=1mA). Bins likely range from the minimum 200 µcd to the maximum 650 µcd. Designers requiring consistent brightness across multiple displays in a product should specify or select units from the same intensity bin. The datasheet does not specify separate bins for wavelength or forward voltage, suggesting tighter manufacturing control or less critical variation in those parameters for this product line.

4. Performance Curve Analysis

While the provided datasheet excerpt mentions typical characteristic curves, the specific graphs are not included in the text. Typically, such curves would include:

• Relative Luminous Intensity vs. Forward Current (I-V Curve): This graph would show how light output increases with current, typically in a sub-linear fashion, highlighting the efficiency roll-off at higher currents.
• Forward Voltage vs. Forward Current: Illustrating the diode's exponential I-V relationship, important for understanding voltage requirements at different drive currents.
• Relative Luminous Intensity vs. Ambient Temperature: This curve is critical, showing the decrease in light output as the junction temperature rises. It directly relates to the current derating specification.
• Spectral Distribution: A plot showing the intensity of emitted light across wavelengths, centered around 650 nm with the specified 20 nm half-width.

These curves are essential for advanced design, allowing engineers to model performance under non-standard conditions and optimize drive circuitry for efficiency and longevity.

5. Mechanical and Package Information

The LTS-360JD features a standard LED display package. The key mechanical specification is the digit height of 0.36 inches (9.1 mm). The package has a gray face with white segments, which enhances contrast when the LEDs are off and diffuses the emitted light for uniform segment appearance when lit. The device utilizes a 10-pin single-row configuration. A detailed dimensioned drawing would typically show the overall width, height, and depth, segment dimensions, pin spacing (likely a standard 0.1" or metric equivalent), and the position of the right-hand decimal point. Tolerances are noted as ±0.25 mm unless otherwise specified.

6. Soldering and Assembly Guidelines

Adherence to the soldering profile is mandatory to ensure reliability. The specified condition is 260°C for 3 seconds, measured at a point 1/16 inch (approximately 1.6 mm) below the seating plane of the package. This is a standard lead-free reflow profile. Designers must ensure their PCB reflow oven profile matches this requirement. Hand soldering with an iron should be performed quickly and with controlled temperature to avoid localized overheating. The device should be stored in a dry, anti-static environment prior to use. After soldering, cleaning should use solvents compatible with the plastic package material.

7. Packaging and Ordering Information

The part number is LTS-360JD. Standard packaging for such discrete LED components is typically on anti-static tape and reel for automated assembly, or in tubes. The specific quantity per reel or tube would be defined in a separate packaging specification. The "Rt. Hand Decimal" note in the description table confirms the device includes a decimal point on the right side of the digit.

8. Application Suggestions

8.1 Typical Application Scenarios

• Digital Multimeters and Bench Instruments: Providing clear, bright readouts of measured values.
• Appliance Control Panels: Displaying timer counts, temperature settings, or operational modes on ovens, microwaves, or washing machines.
• Industrial Control Systems: Showing setpoints, counters, or error codes on machinery HMIs.
• Automotive Aftermarket Displays: Used in auxiliary gauges (voltmeters, tachometers) where high visibility is needed.
• Gaming Devices and Vending Machines: Displaying scores, credits, or selection numbers.

8.2 Design Considerations

• Current Limiting: External resistors are required for each cathode pin (or for the common anode) to set the desired forward current. Calculate resistor value using R = (Vsupply - VF) / IF.
• Multiplexing: To control multiple digits, a multiplexed drive scheme is common. This uses the peak current rating. Ensure the average current over time respects the continuous current rating.
• Viewing Angle: The wide viewing angle is beneficial but consider the mounting orientation relative to the user's line of sight.
• ESD Protection: While not explicitly stated, standard ESD handling precautions for LEDs should be observed during assembly.

9. Technical Comparison and Differentiation

The primary differentiating advantage of the LTS-360JD is its use of AlInGaP on a non-transparent GaAs substrate for hyper red emission. Compared to older technologies like standard GaAsP (Gallium Arsenide Phosphide) red LEDs, AlInGaP offers significantly higher luminous efficiency, resulting in greater brightness for the same drive current, or equivalent brightness at lower power. It also provides superior color saturation and stability over temperature and time. Compared to white LEDs with filters, it offers simpler drive circuitry (no phosphor) and potentially longer lifetime. The 0.36-inch digit height positions it in a mid-range size category, larger than miniature SMD 7-segment displays but smaller than large panel-mount digits, offering a good balance between visibility and board space.

10. Frequently Asked Questions (Based on Technical Parameters)

Q: Can I drive this display directly from a 5V microcontroller pin?
A: No. The typical forward voltage is 2.6V, and a microcontroller pin cannot source 20mA safely while also dropping voltage. You must use a current-limiting resistor and likely a transistor or driver IC to handle the current.

Q: What is the purpose of having two common anode pins (Pin 1 and Pin 6)?
A> The two anode pins are internally connected. This design provides mechanical symmetry, simplifies PCB trace routing for the common power connection, and can help distribute current more evenly, potentially improving reliability.

Q: How do I achieve different brightness levels?
A> Brightness can be controlled by varying the forward current (within the maximum ratings) or, more commonly and efficiently, by using Pulse Width Modulation (PWM) on the drive signals. This switches the LED on and off rapidly, controlling the average light output.

Q: Is the decimal point always on?
A> No. The decimal point is a separate LED segment with its own cathode (Pin 7). It is controlled independently, just like segments A-G.

11. Practical Design and Usage Case

Consider designing a simple digital counter using a microcontroller and four LTS-360JD displays. The microcontroller would have insufficient I/O pins to drive each segment of each digit statically (4 digits * 8 segments = 32 lines). Therefore, a multiplexed design is employed. The four common anode pins (one per digit) are connected to four microcontroller pins via PNP transistors (to source the higher current). All corresponding segment cathodes (e.g., all 'A' segments) are tied together and connected to the microcontroller port through a current-limiting resistor network. The microcontroller rapidly cycles through enabling each digit one at a time while outputting the segment pattern for that digit. Due to persistence of vision, all digits appear to be continuously lit. The peak current per segment during its brief on-time can be higher (e.g., 60mA) to achieve good average brightness, while the average current remains below the 25mA continuous rating.

12. Technical Principle Introduction

The LTS-360JD is based on solid-state lighting technology. The core light-emitting element is an AlInGaP semiconductor chip. When a forward voltage exceeding the diode's threshold is applied, electrons and holes are injected into the active region of the semiconductor. Their recombination releases energy in the form of photons (light). The specific composition of the Aluminum, Indium, Gallium, and Phosphide in the crystal lattice determines the bandgap energy, which directly dictates the wavelength (color) of the emitted light—in this case, hyper red at ~650 nm. The non-transparent GaAs substrate absorbs any downward-emitted light, improving contrast by reducing internal reflection. The gray face and white segment mask further enhance contrast by absorbing ambient light and efficiently scattering the emitted red light towards the viewer.

13. Technology Trends and Context

While discrete seven-segment LED displays like the LTS-360JD remain highly relevant for specific applications requiring simplicity, robustness, and high visibility, broader trends in display technology are evident. There is a general shift towards integrated dot-matrix LED displays and OLEDs for applications requiring alphanumeric or graphical output, as they offer greater flexibility. For numeric-only displays, surface-mount device (SMD) seven-segment LEDs are becoming more common to facilitate automated assembly and reduce product thickness. However, through-hole displays like the LTS-360JD maintain advantages in prototyping, repair-ability, and applications subject to high vibration or where through-hole connections are deemed more mechanically robust. The underlying AlInGaP technology continues to be optimized for efficiency and reliability, ensuring such devices meet modern performance and longevity expectations.