LTA-1000M-01 LED Light Bar Datasheet - 10-Segment Rectangular Array - Green/Yellow/Red Colors - 2.6V Forward Voltage - 75mW Power Dissipation - English Technical Document

1. Product Overview

The LTA-1000M-01 is a multi-color, solid-state light source designed as a ten-segment rectangular bar array. Its primary function is to provide a large, bright, and uniform emitting area for applications requiring continuous illumination. The device integrates three distinct LED chip technologies within a single package: green LEDs utilizing GaP (Gallium Phosphide) on a transparent GaP substrate, yellow LEDs made from GaAsP (Gallium Arsenide Phosphide) on a transparent GaP substrate, and high-efficiency red LEDs also based on GaAsP on a transparent GaP substrate. This combination allows for versatile visual signaling. The package features a black face for high contrast and white segments to enhance light diffusion and uniformity.

1.1 Core Advantages and Target Market

The device offers several key benefits that make it suitable for a range of industrial and consumer applications. Its large and bright emitting area ensures excellent visibility. The low power requirement contributes to energy efficiency. High brightness and contrast are achieved through the chip technology and the black/white package design. Solid-state reliability ensures long operational life with minimal maintenance. The device is also categorized for luminous intensity, providing consistency in performance, and is offered in a lead-free package compliant with RoHS (Restriction of Hazardous Substances) directives. Typical applications include status indicator panels, industrial control system displays, instrumentation, and any equipment where a clear, multi-segment light source is needed for signaling or information display.

2. In-Depth Technical Parameter Analysis

The following sections provide a detailed breakdown of the device's electrical, optical, and physical specifications.

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. They are specified at an ambient temperature (Ta) of 25°C.

• Power Dissipation per Segment: 75 mW for Green and Hi-Eff Red; 60 mW for Yellow.
• Peak Forward Current per Segment: 100 mA for Green and Hi-Eff Red; 80 mA for Yellow. This is applicable under pulsed conditions (1/10 duty cycle, 0.1ms pulse width).
• Continuous Forward Current per Segment: 25 mA for Green/Red, 20 mA for Yellow, with a linear derating factor of 0.33 mA/°C and 0.27 mA/°C respectively above 25°C.
• Reverse Voltage per Segment: 5 V for all colors.
• Operating & Storage Temperature Range: -35°C to +105°C.
• Soldering: Recommended condition is 260°C for 3 seconds at 1/16 inch (approx. 1.6mm) below the seating plane.

2.2 Electrical & Optical Characteristics

These are typical performance parameters measured at Ta=25°C. The luminous intensity is measured using a sensor and filter approximating the CIE photopic eye-response curve.

2.2.1 Green LED Characteristics (IF=10mA unless noted)

• Average Luminous Intensity (Iv): 800 μcd (Min), 2800 μcd (Typ).
• Peak Emission Wavelength (λp): 565 nm (Typ, at IF=20mA).
• Spectral Line Half-Width (Δλ): 30 nm (Typ, at IF=20mA).
• Dominant Wavelength (λd): 569 nm (Typ, at IF=20mA).
• Forward Voltage per Segment (VF): 2.1 V (Min), 2.6 V (Typ) at IF=20mA.
• Reverse Current per Segment (IR): 100 μA (Max) at VR=5V.
• Luminous Intensity Matching Ratio (Iv-m): 2:1 (Typ).

2.2.2 Yellow LED Characteristics (IF=10mA unless noted)

• Average Luminous Intensity (Iv): 540 μcd (Min), 2000 μcd (Typ).
• Peak Emission Wavelength (λp): 585 nm (Typ, at IF=20mA).
• Spectral Line Half-Width (Δλ): 35 nm (Typ, at IF=20mA).
• Dominant Wavelength (λd): 588 nm (Typ, at IF=20mA).
• Forward Voltage per Segment (VF): 2.1 V (Min), 2.6 V (Typ) at IF=20mA.
• Reverse Current per Segment (IR): 100 μA (Max) at VR=5V.
• Luminous Intensity Matching Ratio (Iv-m): 2:1 (Typ).

2.2.3 High-Efficiency Red LED Characteristics (IF=10mA unless noted)

• Average Luminous Intensity (Iv): 540 μcd (Min), 2000 μcd (Typ).
• Peak Emission Wavelength (λp): 650 nm (Typ, at IF=20mA).
• Spectral Line Half-Width (Δλ): 40 nm (Typ, at IF=20mA).
• Dominant Wavelength (λd): 630 nm (Typ, at IF=20mA).
• Forward Voltage per Segment (VF): 2.1 V (Min), 2.6 V (Typ) at IF=20mA.
• Reverse Current per Segment (IR): 100 μA (Max) at VR=5V.
• Luminous Intensity Matching Ratio (Iv-m): 2:1 (Typ) for similar light area.

3. Binning System Explanation

The datasheet indicates the device is \"categorized for luminous intensity.\" This implies a binning process where LEDs are sorted based on measured light output at a standard test current (10mA in this case). The specified \"Luminous Intensity Matching Ratio\" of 2:1 (Typical) indicates that within a given batch or category, the intensity of individual segments should not vary by more than a factor of two. While specific bin codes are not provided in this excerpt, designers should be aware that actual purchased devices will fall within the Min and Typ intensity ranges listed, ensuring a degree of uniformity in application.

4. Performance Curve Analysis

The datasheet references \"Typical Electrical / Optical Characteristic Curves\" on the final page. Although the specific curves are not detailed in the provided text, such graphs typically include:

• Forward Current vs. Forward Voltage (I-V Curve): Shows the exponential relationship, crucial for designing current-limiting circuitry.
• Luminous Intensity vs. Forward Current: Demonstrates how light output increases with current, up to the maximum ratings.
• Luminous Intensity vs. Ambient Temperature: Shows the derating of light output as temperature increases, which is critical for thermal management.
• Spectral Distribution: A plot of relative intensity vs. wavelength, illustrating the peak and dominant wavelengths and the spectral width.

These curves are essential for understanding the device's behavior under non-standard conditions (different currents, temperatures) and for optimizing the design for performance and longevity.

5. Mechanical and Package Information

5.1 Package Dimensions

The device has a rectangular light bar form factor. All dimensions are in millimeters (mm). The general tolerance is ±0.25 mm unless otherwise specified. A key note is that the pin tip shift tolerance is ±0.4 mm, which is important for PCB (Printed Circuit Board) footprint design to ensure proper alignment and soldering.

5.2 Pin Connection and Polarity

The LTA-1000M-01 features a 20-pin configuration. The pinout is organized in a complementary anode-cathode arrangement:

• Pins 1-10: Anodes for segments A through K (note: segment I is skipped, using J and K).
• Pins 11-20: Cathodes for segments K through A, in reverse order.

This arrangement likely facilitates common-cathode or independent driving configurations for the ten segments. The internal circuit diagram (referenced but not shown in detail) would clarify the exact connection of each anode/cathode pair to its respective LED segment.

5.3 Polarity Identification

While not explicitly stated in the text, polarity is defined by the anode and cathode pins. Proper identification during assembly is critical to prevent reverse bias, which is limited to 5V as per the Absolute Maximum Ratings.

6. Soldering and Assembly Guidelines

The datasheet provides a specific soldering condition: 260°C for 3 seconds, measured at 1/16 inch (approximately 1.6 mm) below the seating plane of the component. This is a typical reflow soldering parameter. It is crucial to adhere to this profile to avoid exceeding the device's maximum temperature rating, which could damage the LED chips or the package material. The broad storage and operating temperature range (-35°C to +105°C) indicates good resilience to environmental stresses, but the soldering process involves localized high heat that must be carefully controlled.

7. Application Suggestions and Design Considerations

7.1 Typical Application Scenarios

This light bar is ideal for applications requiring a multi-segment, bar-graph style display or a set of independent status indicators. Examples include: audio equipment VU meters, battery charge level indicators, process control gauges, diagnostic panels on medical or industrial equipment, and status displays on telecommunications hardware.

7.2 Design Considerations

• Current Limiting: LEDs are current-driven devices. An external current-limiting resistor or constant-current driver circuit is mandatory for each segment or bank of segments to prevent exceeding the maximum continuous forward current (20-25 mA). The resistor value can be calculated using the typical forward voltage (2.6V) and the desired operating current.
• Thermal Management: While power dissipation is low per segment (60-75 mW), driving multiple segments simultaneously or operating in high ambient temperatures requires consideration of the derating curve for continuous current. Adequate PCB copper area or other cooling methods may be necessary in demanding environments.
• Driving Circuitry: The pinout allows for flexible driving. A microcontroller with sufficient I/O pins can independently address each segment. For simpler on/off control, segments can be grouped by connecting their anodes or cathodes together.
• Visual Design: The black face provides high contrast when the LEDs are off. The white segments help blend the light from the discrete LED chips into a more uniform rectangular bar of light.

8. Technical Comparison and Differentiation

The LTA-1000M-01 differentiates itself through its specific combination of features:

• Multi-Chip Technology in One Package: Integrating three different semiconductor materials (GaP for green, GaAsP for yellow/red) into a single device is a notable design that offers color variety without needing multiple component types.
• Rectangular Bar Format: Compared to discrete round LEDs, this bar format provides a larger and more visually continuous light area, which is preferable for certain types of indicators and displays.
• High Contrast Package: The black face and white segment design is optimized for readability, a feature not always present in standard LED packages.
• Lead-Free & RoHS Compliant: This ensures the component meets modern environmental regulations for electronic manufacturing.

9. Frequently Asked Questions (Based on Technical Parameters)

Q: Can I drive all ten segments at their maximum continuous current simultaneously?

A: Possibly, but you must calculate the total power dissipation and ensure the PCB and environment can handle the heat. The derating factor for current above 25°C must be applied. It is often safer to operate below the absolute maximum.

Q: What is the difference between \"Peak Emission Wavelength\" and \"Dominant Wavelength\"?

A: Peak wavelength is the point of highest intensity in the spectral output. Dominant wavelength is the single wavelength of monochromatic light that would appear to have the same color to the human eye. Dominant wavelength is more relevant for perceived color.

Q: The forward voltage is listed as 2.1V Min and 2.6V Typ. Which should I use for my circuit calculations?

A: For a robust design, use the maximum typical value (2.6V) to ensure sufficient voltage is supplied across the current-limiting resistor under all conditions. Using the minimum could lead to excessive current if the actual Vf of your device is higher.

Q: What does a \"Luminous Intensity Matching Ratio of 2:1\" mean in practice?

A: It means that within a group of these devices (or segments), the brightest one should ideally be no more than twice as bright as the dimmest one when driven under the same conditions. This ensures visual consistency in your display.

10. Practical Use Case Example

Scenario: Designing a 10-stage battery charge indicator for a portable device.

The LTA-1000M-01 is an excellent choice. Segments can be assigned to represent 10% charge increments. A microcontroller's ADC (Analog-to-Digital Converter) monitors the battery voltage. Based on the charge level, the MCU turns on the corresponding number of LED segments (e.g., 7 segments for 70% charge). The green segments could be used for high charge (e.g., 70-100%), yellow for medium (30-60%), and red for low charge (0-20%) to provide intuitive color coding. The current for each segment would be set to 15-20 mA via individual resistors connected to the MCU's GPIO pins, configured as current sinks for the cathodes (common-anode configuration). The uniform rectangular bars create a clean, professional-looking gauge.

11. Operating Principle Introduction

Light Emitting Diodes (LEDs) are semiconductor devices that emit light through electroluminescence. When a forward voltage is applied across the p-n junction, electrons from the n-type material recombine with holes from the p-type material. This recombination releases energy in the form of photons (light). The specific wavelength (color) of the emitted light is determined by the energy bandgap of the semiconductor material. The LTA-1000M-01 uses:

- GaP (Gallium Phosphide): For green light emission. The transparent GaP substrate allows more light to escape.

- GaAsP (Gallium Arsenide Phosphide): The ratio of arsenic to phosphorus in the crystal lattice determines the color, yielding yellow and high-efficiency red light in this device. The transparent GaP substrate again enhances light extraction efficiency.

12. Technology Trends and Context

The LTA-1000M-01 represents a classic, well-established LED display technology. Current trends in optoelectronics include:

- Increased Efficiency: Newer materials like InGaN (for blue/green/white) and AlInGaP (for red/orange/yellow) offer higher luminous efficacy (more light output per watt) than the older GaP and GaAsP technologies used here.

- Miniaturization & Integration: Trends are towards smaller packages (e.g., chip-scale LEDs) and direct integration of LED drivers and control logic into the package (smart LEDs).

- Color Quality & Uniformity: Modern high-end displays demand tighter color and intensity binning (e.g., 3-step or 5-step MacAdam ellipses) for perfect uniformity, exceeding the 2:1 ratio specified here.

- Flexible & Unconventional Form Factors: Development of flexible substrates and micro-LED arrays is enabling new display types.

Despite these trends, components like the LTA-1000M-01 remain highly relevant for cost-effective, reliable, and straightforward indicator applications where the latest ultra-high efficiency or miniaturization is not the primary requirement. Its strength lies in its simple integration, proven reliability, and the specific visual form factor of the rectangular light bar.