LTC-5836JG LED Display Datasheet - 0.52-inch Digit Height - AlInGaP Green - 2.6V Forward Voltage - English Technical Document

1. Product Overview

The LTC-5836JG is a high-performance, triple-digit, seven-segment LED display module. It is designed for applications requiring clear, bright numeric readouts. The core technology utilizes Aluminium Indium Gallium Phosphide (AlInGaP) semiconductor material grown on a Gallium Arsenide (GaAs) substrate, which is engineered to emit green light. This material system is known for its high efficiency and excellent color purity. The device features a digit height of 0.52 inches (13.2 mm), providing good visibility. The display has a gray faceplate with white segments, which enhances contrast and improves character legibility under various lighting conditions. It employs a common anode configuration, which is a standard design for simplifying drive circuitry in multi-digit displays.

1.1 Core Advantages and Target Market

The primary advantages of this display include its high luminous intensity, excellent character appearance with uniform segment illumination, and a wide viewing angle, ensuring readability from different positions. Its solid-state construction offers high reliability and long operational life compared to other display technologies. The low power requirement makes it suitable for battery-powered or energy-conscious devices. This product is typically targeted at industrial instrumentation, consumer electronics (such as clocks, timers, and appliances), test and measurement equipment, and any application where a reliable, bright, and easy-to-read numeric display is needed.

2. In-Depth Technical Parameter Analysis

The electrical and optical characteristics define the operational boundaries and performance of the LED display. Understanding these parameters is crucial for proper circuit design and system integration.

2.1 Photometric and Optical Characteristics

The key optical parameter is the average luminous intensity per segment. Under a standard test current of 10 mA, the typical value is 577 microcandelas (µcd), with a minimum specified value of 200 µcd. This high brightness level ensures good visibility. The peak emission wavelength (λp) is typically 571 nanometers (nm), placing it firmly in the green region of the visible spectrum. The spectral line half-width (Δλ) is 15 nm, indicating a relatively narrow and pure color emission. The dominant wavelength (λd) is 572 nm. Luminous intensity matching between segments is specified with a maximum ratio of 2:1, which aims to ensure uniform brightness across all segments of a digit for a consistent appearance.

2.2 Electrical Parameters

The forward voltage (VF) per segment is a critical parameter for driver design. At a forward current (IF) of 20 mA, the typical VF is 2.6 volts, with a maximum of 2.6V and a minimum of 2.1V. This voltage range must be considered when selecting current-limiting resistors or designing constant-current drivers. The reverse current (IR) per segment is very low, with a maximum of 100 microamperes (µA) at a reverse voltage (VR) of 5V, indicating good diode characteristics.

2.3 Absolute Maximum Ratings and Thermal Considerations

These ratings define the stress limits beyond which permanent damage may occur. The maximum continuous power dissipation per segment is 70 mW. The peak forward current per segment is 60 mA, but this is only permissible under pulsed conditions (1 kHz frequency, 10% duty cycle) to manage heat generation. The continuous forward current per segment is derated from 25 mA at 25°C at a rate of 0.33 mA/°C. This derating curve is essential for designing reliable systems operating at elevated ambient temperatures. The operating and storage temperature range is specified from -35°C to +85°C, making it suitable for a wide range of environments.

3. Binning System Explanation

The datasheet indicates that the device is categorized for luminous intensity. This implies a binning process where units are sorted based on their measured light output at a standard test current (likely 10 mA). Bins are defined with minimum and maximum intensity values. Designers should be aware that ordering this part may yield displays from a specific intensity bin, which affects overall display brightness consistency, especially if multiple displays are used in a single product. The datasheet does not specify separate bins for wavelength or forward voltage, suggesting tighter control or less variation in these parameters for this product line.

4. Performance Curve Analysis

While the specific curves are not detailed in the provided text, typical characteristic curves for such a device would be essential for design. These usually include:

• IV Curve (Current vs. Voltage): Shows the relationship between forward current and forward voltage, crucial for determining the operating point and designing the drive circuitry.
• Luminous Intensity vs. Forward Current: Demonstrates how light output increases with current, typically in a sub-linear fashion, helping to optimize the trade-off between brightness and power consumption/heat.
• Luminous Intensity vs. Ambient Temperature: Illustrates the decrease in light output as junction temperature rises, which is critical for applications in high-temperature environments.
• Spectral Distribution: A graph showing the relative intensity of emitted light across wavelengths, confirming the peak and dominant wavelength values.

Engineers must consult these curves to predict performance under non-standard operating conditions.

5. Mechanical and Package Information

The device comes in a standard LED display package. The package dimensions are provided in millimeters with a general tolerance of ±0.25 mm. The pin connection diagram is critical for PCB layout. The LTC-5836JG has 30 pins. The internal circuit diagram shows a common anode configuration for each of the three digits, with individual cathodes for each segment (A-G) and decimal point (D.P.). The pinout table meticulously maps each pin to its function (e.g., Pin 3 is Common Anode for Digit 1, Pin 16 is Cathode B for Digit 3). Correct interpretation of this table is mandatory to avoid wiring errors during PCB design.

6. Soldering and Assembly Guidelines

The datasheet specifies a single soldering condition: the device can be subjected to a soldering iron temperature of 260°C for 3 seconds, with the iron tip positioned at least 1/16 inch (approximately 1.59 mm) below the seating plane of the package. This is a guideline for hand soldering or repair. For modern assembly, wave soldering or reflow soldering profiles would be more common. While not specified here, a typical lead-free reflow profile with a peak temperature around 245-260°C would likely be applicable, but the thermal mass of the package must be considered. It is always recommended to perform a process qualification. The storage temperature range is -35°C to +85°C, and devices should be kept in moisture-sensitive packaging if intended for reflow soldering to prevent \"popcorning\" damage.

7. Packaging and Ordering Information

The part number is LTC-5836JG. The \"JG\" suffix likely denotes the green color and specific package or performance variant. The datasheet does not detail bulk packaging (e.g., tubes, trays, or reels) or quantities per package. For production, this information must be obtained from the supplier or distributor. The label on the packaging would typically include the part number, lot code, and possibly intensity bin information.

8. Application Recommendations

8.1 Typical Application Scenarios

This display is ideal for any device requiring a clear, multi-digit numeric readout. Common applications include digital multimeters, frequency counters, process control indicators, weighing scales, medical devices, automotive dashboard displays (for non-critical information), industrial timers, and consumer appliances like ovens or microwave ovens.

8.2 Design Considerations

• Drive Circuitry: Use a constant-current driver or current-limiting resistors for each segment cathode. The common anode for each digit should be switched (e.g., by a transistor) to enable multiplexing, which reduces the number of required I/O pins from a microcontroller.
• Current Calculation: Based on the desired brightness and the IV curve, calculate the appropriate series resistor value using the formula: R = (Vcc - VF) / IF, where Vcc is the supply voltage, VF is the forward voltage (use 2.6V for design margin), and IF is the desired forward current (not exceeding 25 mA continuous).
• Multiplexing: When multiplexing multiple digits, ensure the refresh rate is high enough (typically >60 Hz) to avoid visible flicker. The peak current per segment during the multiplexed on-time must not exceed the absolute maximum ratings.
• Heat Management: Ensure adequate ventilation if operating near maximum current or in high ambient temperatures. Consider the forward current derating curve.
• ESD Protection: LEDs are sensitive to electrostatic discharge. Implement proper ESD handling procedures during assembly.

9. Technical Comparison

Compared to older technologies like red Gallium Arsenide Phosphide (GaAsP) LEDs, the AlInGaP technology in the LTC-5836JG offers significantly higher luminous efficiency, resulting in brighter displays for the same current, or similar brightness at lower power. The green color is often perceived as more comfortable for extended viewing than red. Compared to dot-matrix or graphic OLEDs, this seven-segment display is simpler, more cost-effective for numeric-only applications, and typically offers higher brightness and longer lifetime, though it lacks alphanumeric or graphical capability.

10. Frequently Asked Questions (Based on Technical Parameters)

Q: What is the purpose of the \"common anode\" configuration?
A: In a common anode display, all the anodes of the LEDs in a digit are connected together to a single pin. This allows the microcontroller to control which digit is active by supplying voltage (through a switch) to this common anode, while the individual segment cathodes are controlled to turn specific segments on or off. This greatly reduces the number of microcontroller pins needed.

Q: Can I drive this display with a 5V supply?
A: Yes, but you must use a current-limiting resistor in series with each segment. For example, to achieve a forward current of 20 mA with a VF of 2.6V and a Vcc of 5V, the resistor value would be R = (5V - 2.6V) / 0.02A = 120 Ohms. A standard 120Ω resistor would be suitable.

Q: What does \"categorized for luminous intensity\" mean for my design?
A: It means displays are tested and sorted into groups (bins) based on their brightness. If absolute brightness consistency is critical across all units of your product, you should specify and purchase devices from the same intensity bin from your supplier.

Q: How do I multiplex the three digits?
A: You would connect all corresponding segment cathodes together (e.g., all \"A\" segment cathodes from Digit 1, 2, and 3 to one microcontroller pin via a driver). You then sequentially enable (provide power to) the common anode of Digit 1, then Digit 2, then Digit 3, while outputting the correct segment pattern for each digit. This cycle repeats rapidly.

11. Practical Design and Usage Case

Case: Designing a Digital Timer with Microcontroller. A designer is creating a countdown timer. They use the LTC-5836JG to display minutes and seconds (MM:SS). They connect the 7 segment lines (A-G) and the colon/decimal point lines to output pins of a microcontroller via current-limiting resistors (calculated for 15 mA per segment for a balance of brightness and power). The three common anode pins (one for each digit of minutes and two for seconds) are connected to the microcontroller via NPN transistors acting as low-side switches. The microcontroller firmware runs a timer interrupt at 1 kHz. In the interrupt service routine, it turns off all digit transistors, updates the segment pattern for the next digit to be displayed, turns on the corresponding digit transistor, and then moves to the next digit. This multiplexing scheme uses only 7+3=10 microcontroller I/O pins to control a 3-digit display, demonstrating efficient resource use.

12. Technology Principle Introduction

The LTC-5836JG is based on Aluminium Indium Gallium Phosphide (AlInGaP) semiconductor technology. This is a direct bandgap III-V compound semiconductor. When a forward voltage is applied across the p-n junction, electrons from the n-type region and holes from the p-type region are injected into the active region. These charge carriers recombine, releasing energy in the form of photons (light). The specific composition of Al, In, Ga, and P in the crystal lattice determines the bandgap energy, which directly corresponds to the wavelength (color) of the emitted light. For green emission, the bandgap is engineered to be approximately 2.2 to 2.3 electron volts (eV). The use of a GaAs substrate provides a suitable crystalline template for growing the AlInGaP epitaxial layers. The gray face and white segments are part of the plastic package, which acts as a diffuser and lens to shape the light output from the tiny LED chips into uniform, recognizable segments.

13. Technology Development Trends

The trend in LED display technology is towards higher efficiency, greater integration, and more versatile form factors. While discrete seven-segment displays like the LTC-5836JG remain relevant for cost-sensitive, numeric-only applications, several trends are notable. Firstly, the move towards even more efficient materials like Gallium Nitride (GaN) for blue/green/white and continued refinement of AlInGaP for red/orange/yellow/green. Secondly, the integration of driver ICs directly into the display module (\"intelligent displays\") to simplify system design. Thirdly, the growth of surface-mount device (SMD) packages over through-hole types for automated assembly. Finally, the competitive pressure from alternative technologies like Organic LEDs (OLEDs) and Liquid Crystal Displays (LCDs), which offer full graphics capability in thin packages, though often at different price, brightness, and lifetime points. The AlInGaP seven-segment display occupies a stable niche where its simplicity, robustness, high brightness, and low cost are decisive advantages.