LTS-5601AJG-J 0.56-inch Seven-Segment LED Display Datasheet - Digit Height 14.22mm - Green AlInGaP - English Technical Document

1. Product Overview

The LTS-5601AJG-J is a single-digit, seven-segment alphanumeric display module designed for applications requiring clear, bright numeric readouts. It features a digit height of 0.56 inches (14.22 mm), providing excellent visibility. The device utilizes advanced AlInGaP (Aluminum Indium Gallium Phosphide) semiconductor technology for its light-emitting segments, which are presented in a vibrant green color against a neutral gray background face. This combination offers high contrast for optimal legibility. The display employs a common anode electrical configuration, which is a standard and widely supported interface in digital circuit design.

1.1 Core Advantages

The display offers several key benefits for designers and engineers. Its primary advantage is the use of AlInGaP LED chips, which are known for their high efficiency and excellent luminous intensity, resulting in a bright output with relatively low power consumption. The continuous, uniform segments ensure a consistent and professional character appearance without gaps or irregularities. The device is categorized for luminous intensity, providing consistency in brightness across production batches. Furthermore, it features a wide viewing angle, making the display readable from various positions, and offers solid-state reliability with no moving parts. The package is also lead-free, complying with modern environmental regulations (RoHS).

1.2 Target Market and Applications

This display is suitable for a wide range of electronic equipment requiring numeric indication. Typical applications include test and measurement instruments (multimeters, oscilloscopes), industrial control panels, medical devices, consumer appliances (microwaves, ovens, washing machines), automotive dashboards (for aftermarket or auxiliary displays), and various hobbyist or prototyping projects. Its balance of size, brightness, and reliability makes it a versatile choice for both commercial and industrial embedded systems.

2. Technical Parameter Deep Dive

This section provides a detailed, objective analysis of the electrical and optical specifications provided in the datasheet.

2.1 Photometric and Optical Characteristics

The optical performance is central to the display's functionality. The Average Luminous Intensity (Iv) is specified with a minimum of 125 µcd, a typical value of 400 µcd, and no stated maximum, when driven at a forward current (IF) of 1 mA. This indicates a guaranteed minimum brightness, with most units performing significantly brighter. The Peak Emission Wavelength (λp) is 571 nm, and the Dominant Wavelength (λd) is 572 nm, both measured at IF=20mA. These values firmly place the emitted light in the green region of the visible spectrum. The Spectral Line Half-Width (Δλ) is 15 nm, which describes the purity of the green color; a narrower width indicates a more monochromatic output. The Luminous Intensity Matching Ratio is specified as 2:1 maximum for similar light areas, meaning the brightness difference between any two segments should not exceed a factor of two, ensuring uniform appearance.

2.2 Electrical Parameters

The electrical specifications define the operating limits and conditions for the device. The Forward Voltage per Segment (VF) has a typical value of 2.6V and a maximum of 2.6V at IF=20mA. This is a critical parameter for designing the current-limiting resistor network. The Continuous Forward Current per Segment is rated at 25 mA maximum, with a derating factor of 0.33 mA/°C above 25°C ambient temperature. This means the allowable current decreases as temperature rises to prevent overheating. A Peak Forward Current of 60 mA is allowed under pulsed conditions (1/10 duty cycle, 0.1ms pulse width), which can be used for multiplexing or achieving higher instantaneous brightness. The Reverse Voltage (VR) rating is 5V, and the Reverse Current (IR) is a maximum of 100 µA at this voltage, indicating the diode's leakage characteristics in the off state.

2.3 Absolute Maximum Ratings and Thermal Considerations

These ratings define the stress limits beyond which permanent damage may occur. The Power Dissipation per Segment must not exceed 70 mW. The Operating Temperature Range is from -35°C to +105°C, and the Storage Temperature Range is identical. This wide range makes the device suitable for harsh environments. The datasheet also specifies soldering conditions: the unit can be subjected to 260°C for 3 seconds at a distance of 1/16 inch (approximately 1.6 mm) below the seating plane. Adhering to these limits is crucial during PCB assembly to avoid thermal damage to the LED chips or the plastic package.

3. Binning System Explanation

The datasheet indicates that the device is categorized for luminous intensity. This refers to a manufacturing binning process where LEDs are sorted based on their measured light output at a standard test current (typically 1 mA, as noted). Units are grouped into bins with defined minimum and maximum intensity ranges. This ensures that customers receive displays with consistent brightness levels. While the specific bin codes are not detailed in this excerpt, designers should be aware that such categorization exists and may need to specify a required bin for critical applications where brightness matching between multiple displays is essential.

4. Performance Curve Analysis

The datasheet references Typical Electrical/Optical Characteristic Curves. Although the specific graphs are not provided in the text, standard curves for such devices typically include:

• Forward Current vs. Forward Voltage (I-V Curve): This non-linear curve shows how voltage increases with current. It is essential for determining the correct series resistor value to achieve the desired operating current.
• Luminous Intensity vs. Forward Current (I-L Curve): This shows the relationship between drive current and light output. It is generally linear over a range but may saturate at higher currents.
• Luminous Intensity vs. Ambient Temperature: This curve demonstrates how light output decreases as the junction temperature of the LED increases. Understanding this derating is key for designs operating in high-temperature environments.
• Spectral Distribution: A graph showing the relative intensity of light across different wavelengths, centered around the peak wavelength of 571 nm.

Designers should consult these curves, when available, to optimize performance and ensure reliable operation across the intended temperature and current ranges.

5. Mechanical and Package Information

5.1 Dimensions and Tolerances

The package drawing (referenced but not detailed in text) would show the physical outline of the display. Key notes from the datasheet state that all dimensions are in millimeters, with general tolerances of ±0.25 mm (0.01") unless otherwise specified. A specific tolerance for pin tip shift is ±0.4 mm, which is important for PCB footprint design to ensure proper alignment and solderability.

5.2 Pin Configuration and Internal Circuit

The device has a 10-pin single-row configuration. The internal circuit diagram shows a common anode configuration, where the anodes of all LED segments (A through G and the Decimal Point) are connected internally to two common pins (Pin 3 and Pin 8). The individual segment cathodes are brought out to separate pins. This configuration is common because it simplifies multiplexing when driving multiple digits, as the common anodes can be switched to select which digit is active.

The pin connection table is as follows:

1. Pin 1: Cathode E
2. Pin 2: Cathode D
3. Pin 3: Common Anode
4. Pin 4: Cathode C
5. Pin 5: Cathode D.P. (Decimal Point)
6. Pin 6: Cathode B
7. Pin 7: Cathode A
8. Pin 8: Common Anode
9. Pin 9: Cathode F
10. Pin 10: Cathode G

5.3 Polarity Identification

The device is clearly marked as a Common Anode type. Physically, there may be a notch, dot, or beveled corner on the package to indicate pin 1. Designers must cross-reference the pinout diagram with the physical package to ensure correct orientation during PCB assembly. Incorrect polarity will prevent the display from lighting.

6. Soldering and Assembly Guidelines

The primary guidance provided is for the soldering process. The component can withstand wave or reflow soldering with a peak temperature of 260°C for a maximum of 3 seconds, measured at a point 1.6 mm (1/16") below the seating plane. This is a standard JEDEC profile. It is critical to control the soldering time and temperature to prevent the plastic package from warping or the internal wire bonds from being damaged by excessive heat. Preheating is recommended to minimize thermal shock. After soldering, the display should be allowed to cool naturally. Avoid applying mechanical stress to the pins or the face of the display during handling and assembly.

7. Packaging and Ordering Information

The part number is LTS-5601AJG-J. A typical breakdown of such a part number could be: LTS (product family), 5601 (size/code), A (color/brightness bin?), J (package type?), G (Green), -J (suffix for variations like right-hand decimal point). The datasheet confirms the description as "AlInGaP Green Common Anode, Rt. Hand Decimal." This indicates the decimal point is positioned on the right side of the digit. Displays are typically supplied in anti-static tubes or trays to protect the pins and prevent electrostatic discharge damage during shipping and handling.

8. Application Recommendations

8.1 Typical Application Circuits

For a common anode display, the driving circuit typically involves connecting the common anode pin(s) to the positive supply voltage (Vcc) through a current-limiting resistor or a transistor switch (for multiplexing). Each individual cathode pin (A-G, DP) is then connected to the output of a driver IC, such as a 7-segment decoder/driver (e.g., 74LS47 for BCD input) or a microcontroller GPIO pin. The driver sinks current to ground to illuminate the segment. The value of the current-limiting resistor is calculated using Ohm's Law: R = (Vcc - VF) / IF, where VF is the forward voltage of the LED (typically 2.6V) and IF is the desired forward current (e.g., 10-20 mA).

8.2 Design Considerations

• Current Limiting: Always use series resistors for each segment or a constant current driver. Never connect the LED directly to a voltage source.
• Multiplexing: To drive multiple digits, multiplex the common anodes at a high frequency (e.g., >100 Hz). This reduces the number of required driver pins significantly.
• Power Dissipation: Ensure the total power dissipated (IF * VF * number of lit segments) does not exceed the package's thermal limits, especially in high ambient temperatures.
• Viewing Angle: Mount the display considering the specified wide viewing angle to ensure the intended audience can see it clearly.
• ESD Protection:** Although not explicitly stated, LEDs are sensitive to electrostatic discharge. Handle with appropriate ESD precautions during assembly.

9. Technical Comparison

Compared to older technologies like standard GaP (Gallium Phosphide) green LEDs, the AlInGaP technology used in this display offers significantly higher luminous efficiency, resulting in brighter output at the same current or equivalent brightness at lower power. Compared to blue-chip + phosphor white LEDs, this monochromatic green LED has a narrower spectrum and potentially higher efficacy for applications where only green light is needed. The 0.56-inch digit height is a common size, offering a good balance between readability and board space consumption, larger than 0.3-inch displays for better visibility but smaller than 1-inch displays for compactness.

10. Frequently Asked Questions (FAQs)

Q: What is the difference between common anode and common cathode?
A: In a common anode display, all segment anodes are connected together to Vcc, and segments are turned ON by pulling their cathodes LOW (to ground). In a common cathode display, all cathodes are connected to ground, and segments are turned ON by applying a HIGH voltage (Vcc) to their anodes. The driving circuitry differs accordingly.

Q: Can I drive this display directly from a microcontroller pin?
A: A typical microcontroller GPIO pin can sink or source only 20-25 mA. You can drive a single segment directly if you include a series resistor and stay within the MCU's current limits. For multiple segments or multiplexing, use dedicated driver ICs or transistor arrays to handle the higher cumulative current.

Q: The datasheet lists two common anode pins (3 and 8). Should I connect both?
A: Yes, for maximum reliability and current distribution, it is recommended to connect both common anode pins to the power supply. This helps balance the current load, especially when multiple segments are illuminated simultaneously.

Q: How do I calculate the resistor value for a 5V supply and 10 mA segment current?
A: Using VF(typ) = 2.6V: R = (5V - 2.6V) / 0.01A = 240 Ohms. A standard 220 or 270 Ohm resistor would be suitable. Always verify brightness and current in the actual circuit.

11. Practical Use Case Example

Project: Simple Digital Voltmeter Display
In a basic digital voltmeter built around a microcontroller with an analog-to-digital converter (ADC), the LTS-5601AJG-J can be used to display the measured voltage. The microcontroller reads the ADC value, converts it to a voltage, and formats it into digits (e.g., "12.5"). Using a multiplexing technique, the MCU would sequentially enable the common anode of each digit (for a multi-digit display built from several units) and output the cathode pattern for the corresponding segment data for that digit. A driver IC like the MAX7219 could be used to simplify the interface, handling both multiplexing and current control for the microcontroller. The high brightness of the AlInGaP segments ensures the reading is clear even in well-lit environments.

12. Technical Principle Introduction

The LTS-5601AJG-J is based on AlInGaP (Aluminum Indium Gallium Phosphide) semiconductor material. When a forward voltage is applied across the p-n junction of the LED chip, electrons and holes recombine, releasing energy in the form of photons. The specific composition of the AlInGaP alloy determines the bandgap energy, which directly corresponds to the wavelength (color) of the emitted light—in this case, green at around 571-572 nm. The chips are mounted on a non-transparent GaAs substrate, which helps in directing light out through the top of the chip. The gray face filter absorbs ambient light, improving contrast by reducing reflections and making the illuminated green segments appear more vivid.

13. Technology Trends

While discrete seven-segment displays remain vital for many applications, the overall trend in display technology is towards integration and flexibility. This includes the growth of dot-matrix LED displays and OLEDs that can show arbitrary graphics and characters. However, for dedicated numeric readouts, seven-segment LEDs like the LTS-5601AJG-J continue to be favored for their simplicity, reliability, low cost, and exceptional readability. Advancements in LED materials, like improved AlInGaP and InGaN (for blue/green), continue to push efficiency and brightness higher. Furthermore, there is a constant drive towards miniaturization and surface-mount packages, although through-hole types like this one persist due to their robustness and ease of prototyping.