LTS-4301JG LED Display Datasheet - 0.4-inch Digit Height - AlInGaP Green - 2.6V Forward Voltage - English Technical Document

1. Product Overview

The LTS-4301JG is a compact, high-performance single-digit numeric display module designed for applications requiring clear, bright, and reliable numerical readouts. Its core function is to visually represent the digits 0-9 and some limited alphanumeric characters using its seven individually controllable segments and a decimal point. The device is engineered for integration into a wide range of electronic equipment where space is at a premium but readability is paramount.

The display utilizes advanced Aluminium Indium Gallium Phosphide (AlInGaP) semiconductor technology for its light-emitting elements. This material system is renowned for producing high-efficiency light emission in the red, orange, amber, and yellow-green spectrum. In this specific device, it is tuned to produce a distinct green color. The use of AlInGaP on a non-transparent Gallium Arsenide (GaAs) substrate contributes to the display's high contrast ratio, as the substrate helps prevent internal light scattering, making the unlit "gray face" appear dark and the lit "white segments" appear bright and vivid.

The target market for this component is broad, encompassing industrial control panels, test and measurement equipment, consumer appliances, automotive dashboards (for secondary displays), medical devices, and point-of-sale terminals. Its key value proposition lies in offering a superior visual performance package—characterized by high brightness, excellent contrast, and wide viewing angles—while maintaining solid-state reliability and relatively low power consumption compared to older display technologies like vacuum fluorescent displays (VFDs) or incandescent bulbs.

2. Technical Parameters Deep Dive

2.1 Optical Characteristics

The optical performance is central to the display's functionality. The Average Luminous Intensity (Iv) is specified with a typical value of 850 µcd (microcandelas) at a forward current (I_F) of 1 mA. The minimum is 320 µcd, and there is no maximum specified in the table, indicating a target-driven specification. This parameter defines the perceived brightness of a segment under standard operating conditions. The measurement is performed using a sensor and filter calibrated to the CIE photopic luminosity function, which mimics the spectral sensitivity of the human eye under normal lighting conditions, ensuring the reported value correlates directly with visual perception.

The color characteristics are defined by wavelength parameters. The Peak Emission Wavelength (λ_p) is 571 nm, which is the wavelength at which the optical power output is maximum. The Dominant Wavelength (\u03bb_d) is 572 nm; this is the single wavelength of monochromatic light that matches the perceived color of the LED's output most closely. The close proximity of these two values (571 nm vs. 572 nm) indicates a spectrally pure green color with minimal shift between the physical peak and the perceived hue. The Spectral Line Half-Width (\u0394\u03bb) is 15 nm, representing the bandwidth over which the emitted light's intensity is at least half of its peak value. A narrower half-width generally indicates a more saturated, purer color.

Luminous Intensity Matching Ratio (I_V-m) is specified as 2:1 maximum. This is a critical parameter for display uniformity, ensuring that the brightness difference between the dimmest and brightest segment within a single digit does not exceed a factor of two when driven under identical conditions. This ratio is vital for achieving a consistent and professional-looking numeric character.

2.2 Electrical Characteristics

The electrical specifications define the operating boundaries and conditions for reliable use. The Forward Voltage per Segment (V_F) has a typical value of 2.6V and a maximum of 2.6V at I_F=20 mA. The minimum is listed as 2.05V. This forward voltage is characteristic of AlInGaP technology and is crucial for designing the current-limiting circuitry, typically resistors, for each segment.

The Reverse Current per Segment (I_R) is a maximum of 100 µA at a Reverse Voltage (V_R) of 5V. This parameter indicates the level of leakage current when the LED is reverse-biased, which is generally very low for solid-state devices.

Absolute Maximum Ratings set the hard limits for device survival. Key ratings include:
- Continuous Forward Current per Segment: 25 mA (derated linearly from 25\u00b0C).
- Peak Forward Current per Segment: 60 mA (allowed under pulsed conditions: 1/10 duty cycle, 0.1 ms pulse width).
- Power Dissipation per Segment: 70 mW.
- Reverse Voltage per Segment: 5 V.
Operating or exceeding these limits risks permanent damage to the LED chips.

2.3 Thermal and Environmental Characteristics

The device is rated for an Operating Temperature Range of -35°C to +85°C. This wide range makes it suitable for applications in harsh environments, from freezing outdoor conditions to hot industrial settings. The Storage Temperature Range is identical (-35°C to +85°C).

A critical assembly parameter is the Solder Temperature specification: the device can withstand 260\u00b0C for 3 seconds at a point 1/16 inch (approximately 1.6 mm) below the seating plane. This is a standard reference for wave soldering or reflow soldering processes, guiding manufacturers on thermal profile setup to avoid damaging the plastic package or the internal wire bonds.

3. Binning System Explanation

The datasheet explicitly states that the device is An rarraba don Ƙarfin HaskakawaWannan yana nuna cewa masana'anta suna amfani da tsarin binning ko rarrabawa. A cikin kera LED, akwai bambance-bambance na halitta a cikin fitarwa saboda ƙananan bambance-bambance a cikin girma na epitaxial da sarrafa guntu. Don tabbatar da daidaito ga abokan ciniki, ana gwada LEDs bayan samarwa kuma a raba su zuwa "kwandon" daban-daban bisa ga mahimman sigogi.

Ga LTS-4301JG, babban ma'aunin binning shine ƙarfin haskakawa a ƙayyadadden gwajin na'ura (mai yiwuwa 1 mA ko 20 mA). Ana haɗa na'urori ta yadda duk raka'o'in da ke cikin takamaiman oda ko rukuni suna da ƙarfin haskakawa da ke faɗowa cikin ƙayyadadden iyaka (misali, yaduwar 320-850 µcd da aka ambata a cikin ƙayyadaddun na iya wakiltar daidaitaccen kwandon, ko kuma za a iya samun ƙananan ƙananan kwandon). Wannan yana ba masu zane damar zaɓar nuni tare da tabbataccen mafi ƙarancin haske, yana tabbatar da kamanni iri ɗaya a duk lambobi a cikin shigar da lambobi da yawa. Duk da cewa ba a cikakken bayani a cikin wannan taƙaitaccen takardar bayanan ba, sauran sigogin binning na gama gari na LEDs masu launi na iya haɗawa da tsayin tsayin tsayi (don tabbatar da daidaiton launi) da ƙarfin lantarki na gaba.

4. Performance Curve Analysis

The datasheet references Typical Electrical / Optical Characteristic Curves. While the specific graphs are not provided in the text snippet, standard curves for such a device would typically include:

Relative Luminous Intensity vs. Forward Current (I-V Curve): This graph would show how the light output increases with the driving current. For LEDs, this relationship is generally linear over a significant range but will saturate at very high currents due to thermal effects and efficiency droop. The curve allows designers to choose an operating current that delivers the desired brightness without excessively stressing the device or reducing its lifespan.

Forward Voltage vs. Forward Current: This curve shows the exponential relationship typical of a diode. It is essential for determining the power supply requirements and for calculating the necessary voltage drop across a series current-limiting resistor.

Relative Luminous Intensity vs. Ambient Temperature: The light output of an LED decreases as the junction temperature increases. This curve quantifies that derating, showing the percentage of light output remaining at elevated temperatures (e.g., at 85\u00b0C). This is critical for applications operating in high-temperature environments to ensure the display remains sufficiently bright.

Spectral Distribution Curve: This would be a plot of relative intensity versus wavelength, showing the bell-shaped curve centered around 571-572 nm with the 15 nm half-width. It visually confirms the color purity of the emitted light.

5. Mechanical and Packaging Information

The LTS-4301JG comes in a standard single-digit seven-segment LED package. The Package Dimensions drawing is referenced, with all dimensions provided in millimeters and standard tolerances of \u00b10.25 mm unless otherwise noted. The physical footprint and segment arrangement follow industry-standard patterns for easy replacement and PCB layout.

The Pin Connection is clearly defined for the 10-pin configuration. It is a Common Cathode design, meaning the cathodes (negative terminals) of all segments and the decimal point are connected internally and brought out to two common pins (Pin 3 and Pin 8). Each segment anode (positive terminal) has its own dedicated pin (Pins 1, 2, 4, 5, 6, 7, 9, 10). Pin 6 is specifically for the Decimal Point (D.P.) anode. This common cathode configuration is widely used and simplifies driving circuitry, especially when using multiplexing techniques with microcontroller I/O ports.

The Internal Circuit Diagram visually represents this electrical configuration, showing the eight individual LEDs (segments A-G plus DP) with their anodes separated and their cathodes tied together to the common pins.

6. Soldering and Assembly Guidelines

As mentioned in the thermal characteristics, the key guideline is the solder temperature limit: 260\u00b0C for 3 seconds at 1/16 inch (1.6mm) below the seating plane. This is a critical parameter for process engineers setting up reflow soldering ovens or wave soldering machines. The thermal profile must be designed so that the temperature at the device leads does not exceed this limit for longer than the specified time to prevent package cracking, delamination, or damage to the internal die attach and wire bonds.

Standard ESD (Electrostatic Discharge) precautions should be observed during handling and assembly, as LED chips are sensitive to static electricity. It is recommended to store and handle the devices in anti-static packaging and use grounded workstations.

For cleaning after soldering, standard processes compatible with the device's plastic material (likely epoxy or similar) should be used. Isopropyl alcohol or dedicated electronics cleaners are typically safe, but compatibility should be verified if using aggressive solvents.

7. Application Suggestions

7.1 Typical Application Circuits

The most common drive method for a common cathode display like the LTS-4301JG is using a microcontroller. Each segment anode pin is connected to a microcontroller output pin via a current-limiting resistor. The value of this resistor (R_limit) is calculated using Ohm's Law: R_limit = (V_supply - V_F) / I_F. For a 5V supply, a V_F of 2.6V, and a desired I_F of 10 mA, the resistor would be (5 - 2.6) / 0.01 = 240 Ohms. The two common cathode pins are connected together and then to a microcontroller pin configured as an output set to a logic LOW (0V) to enable the display. To drive multiple digits, multiplexing is used: the segment lines for all digits are connected in parallel, and each digit's common cathode is controlled individually, turning on only one digit at a time in rapid succession. This saves a significant number of I/O pins.

For constant current driving or higher-performance applications, dedicated LED driver ICs (like the MAX7219 or TM1637) can be used. These chips handle multiplexing, current regulation, and sometimes even digit decoding internally, greatly simplifying the software and hardware design.

7.2 Design Considerations

Current Limiting: Never connect an LED directly to a voltage source without a current-limiting mechanism (resistor or constant-current driver). The forward voltage is not a fixed threshold but a characteristic of the current flow; without limitation, current will rise destructively.

Brightness Control: Brightness can be controlled in two main ways: 1) Adjusting the forward current (via the limiting resistor value in a voltage-drive scheme). 2) Using Pulse-Width Modulation (PWM) on the segment or common cathode lines. PWM is more efficient and provides a wider, more linear dimming range.

Viewing Angle: The datasheet claims a "Wide Viewing Angle." For optimal readability, the display should be mounted so that the primary viewing direction is roughly perpendicular to the face of the display. The wide angle provides flexibility for off-axis viewing.

Heat Dissipation: While power dissipation per segment is low (70 mW max), in a multiplexed application where multiple segments are on simultaneously, the total power in the package can add up. Ensure adequate ventilation if the display is enclosed, especially in high ambient temperature environments.

8. Technical Comparison and Advantages

Compared to older seven-segment technologies, the LTS-4301JG offers distinct advantages:
- vs. Incandescent/Lamp-Based Displays: Far lower power consumption, much longer lifetime (tens of thousands of hours vs. hundreds/thousands), higher shock and vibration resistance, and cooler operation.
- vs. Vacuum Fluorescent Displays (VFDs): Lower operating voltage (2-5V vs. tens of volts for VFDs), simpler drive electronics, no requirement for a filament power supply, and typically better performance in high humidity environments. VFDs may offer wider viewing angles and a different color (often blue-green), but LEDs are generally more robust.
- vs. Liquid Crystal Displays (LCDs): LEDs are emissive and self-luminous, offering superior visibility in low or no light without a backlight. They feature faster response times and a broader operating temperature range. LCDs, however, consume far less power for static displays and can render more complex graphics.

The use of AlInGaP Teknolojia, hasa, ikilinganishwa na taa za zamani za kijani za GaP (Gallium Phosphide), hutoa ufanisi mkubwa wa mwanga, na kusababisha maonyesho makubwa zaidi kwa mkondo sawa wa pembejeo, au mwangaza sawa kwa nguvu ya chini. Rangi pia ni iliyojazwa zaidi na inavutia zaidi kwa macho.

9. Frequently Asked Questions (FAQ)

Q: Je, madhumuni ya kuwa na pini mbili za kawaida za cathode (Pini 3 na Pini 8) ni nini?
A: Hii ni hasa kwa usawa wa mitambo na umeme kwenye kifurushi cha mstari-mbili. Inasaidia kusawazisha usambazaji wa mkondo ikiwa sehemu nyingi zimewashwa wakati mmoja na hutoa mabadiliko katika uelekezaji wa PCB. Ndani, pini hizi mbili zimeunganishwa, kwa hivyo unaweza kutumia mojawapo au zote mbili zikiunganishwa pamoja.

Q: Ina iya sarrafa wannan nuni da tsarin microcontroller na 3.3V?
A: I, amma dole ne ka sake lissafta resistor mai iyakancewar halin yanzu. Tare da V_supply na 3.3V da V_F na 2.6V, ƙarfin lantarki a kan resistor shine 0.7V kawai. Don halin yanzu na 10 mA, kana buƙatar resistor na 70 Ohm (0.7V / 0.01A). Tabbatar cewa fil ɗin fitarwar microcontroller zai iya ɗaukar ko samar da halin yanzu da ake buƙata.

Q: The luminous intensity is given in µcd. How bright is that in practice?
A: 850 µcd (0.85 mcd) is a standard brightness for a small indicator LED. For a seven-segment display viewed indoors under normal ambient light, this provides clear and easily readable characters. For sunlight-readable applications, much higher brightness (tens of mcd per segment) would be required.

Q: What does "Rt. Hand Decimal" mean in the description?
A: It indicates the decimal point is positioned on the right-hand side of the digit, which is the standard and most common placement for numeric displays.

10. Operational Principles

The fundamental operating principle is based on electroluminescence in a semiconductor p-n junction. The AlInGaP chip consists of layers of p-type and n-type semiconductor materials. When a forward voltage exceeding the junction's built-in potential (approximately the V_F) is applied, electrons from the n-region and holes from the p-region are injected into the active region where they recombine. In a direct bandgap semiconductor like AlInGaP, a significant portion of these recombinations releases energy in the form of photons (light). The specific wavelength (color) of the emitted light is determined by the bandgap energy of the semiconductor material, which is engineered during the crystal growth process by adjusting the ratios of Aluminium, Indium, Gallium, and Phosphorus.

The seven-segment format is a simple and efficient way to represent numeric digits using a minimal number of independently controlled elements (seven segments plus a decimal point). By illuminating specific combinations of these segments, all ten decimal digits (0-9) and some letters (like A, C, E, F, H, L, P, etc.) can be formed.

11. Technology Trends

While discrete seven-segment LED displays like the LTS-4301JG remain highly relevant for dedicated numeric readouts due to their simplicity, robustness, and cost-effectiveness, broader display technology trends are impacting their application space.

Integration: There is a trend towards integrated display modules that include the LED digits, driver IC, and sometimes a microcontroller in a single package, communicating via serial interfaces (I2C, SPI). This reduces component count and design complexity for the end-user.

Materials Evolution: AlInGaP technology is mature and excellent for red-amber-yellow-green colors. For pure green and blue-green, Indium Gallium Nitride (InGaN) technology often offers higher efficiency. Future displays may utilize advanced phosphor-converted LEDs or micro-LED arrays for even better performance.

Application Shift: For complex alphanumeric or graphical information, dot-matrix LED displays, OLEDs, or TFT LCDs are increasingly used. However, the seven-segment display's unbeatable advantage lies in extreme clarity for numbers, ultra-low cost, and ease of use in applications where only numbers need to be shown, ensuring its continued use in instrumentation, industrial controls, and appliances for the foreseeable future. The trend here is towards higher brightness, lower power consumption, and possibly smarter, addressable versions of this classic form factor.