LTD-4608KF LED Digital Tube Datasheet - 0.4 Inch Character Height - AlInGaP Yellow Orange - 2.6V Forward Voltage - Technical Documentation

1. Product Overview

The LTD-4608KF is a high-performance, two-digit, seven-segment numeric character display module. Its primary function is to provide clear and reliable numeric and limited character indication in a wide range of electronic devices. The core advantage of this device lies in its use of advanced AlInGaP (Aluminum Indium Gallium Phosphide) semiconductor material for manufacturing the LED chips, which offers higher efficiency and color purity compared to older technologies like traditional GaAsP. This results in the key advantages listed in its feature set: high brightness, excellent character appearance with uniform segments, wide viewing angle, and solid-state reliability. The device is classified by luminous intensity and is offered in lead-free packages compliant with environmental regulations. Its low power consumption makes it suitable for battery-powered or energy-saving applications in consumer electronics, industrial instrumentation, test equipment, and panel displays.

2. Fassarar zurfi da gaskiya na Sigogin Fasaha

2.1 Halayen Haske da na Gani

Optical performance is defined under standard test conditions with a forward current (IF) of 20mA per segment.Average Luminous Intensity (IV)Ƙimar al'ada ita ce 44000 µcd (microcandela), mafi ƙarancin ƙayyadaddun ƙima shine 27520 µcd. Wannan siga tana nuna haske mai iya gani na sashin da aka kunna.Matsakaicin daidaitawar ƙarfin haskeTsakanin sassan da aka kunna a cikin yanki mai kama, an ƙayyade matsakaicin 2:1, yana tabbatar da daidaiton gani na gaba ɗaya na nuni. Launi yana ƙayyade taTsawon zango na kololuwar fitarwa (λp)611 nm daBabban tsawon zango (λd)605 nm, wanda ke sanya shi a cikin yankin rawaya-orange na bakan gani.Rabin faɗin layin bakan (Δλ)The full width at half maximum is 17 nm, indicating a relatively narrow spectral distribution, which helps present saturated and pure colors.

2.2 Halayen Lantarki

The key electrical parameters areForward Voltage per Segment (VF), with a typical value of 2.6V and a maximum of 2.6V at 20mA. The minimum is specified as 2.05V. This voltage is crucial for designing current-limiting circuits.Reverse Current per Segment (IR)is a maximum of 100 µA at a Reverse Voltage (VR) of 5V, indicating the leakage current in the off state. Absolute Maximum Ratings define the operational limits: at 25°C,Continuous Forward Current per SegmentIt is 25 mA, and derates linearly at 0.28 mA/°C above this temperature. Under pulse conditions (1/10 duty cycle, 0.1ms pulse width), thePeak Forward Currentis 60 mA. MaximumPower Dissipation per Segmentis 70 mW, maximumReverse Voltageis 5V.

2.3 Ƙimar Zafi da Muhalli

The device'sOperating temperature rangeis rated from -35°C to +105°C,Storage temperature rangeis the same. This wide range ensures functionality in harsh environments. SpecificSoldering conditions: Pins can withstand 260°C for 3 seconds, provided the device body itself does not exceed its maximum rated temperature during assembly. This is crucial for wave soldering or reflow processes.

3. Grading System Description

The datasheet clearly states that the deviceClassification by luminous intensityThis means LED chips are tested and sorted (binned) based on their measured light output under standard test current. The provided minimum (27520 µcd) and typical (44000 µcd) values define the possible bin boundaries. Designers can specify a particular bin to ensure brightness uniformity across multiple displays in a product. The datasheet does not indicate separate binning for this specific model in terms of wavelength (color) or forward voltage, suggesting these parameters are tightly controlled within the stated min/typ/max ranges.

4. Performance Curve Analysis

Although specific graphs are not detailed in the provided text, typical curves for such devices include:

• Relative Luminous Intensity vs. Forward Current (I-V Curve):This graph would show how light output increases with current, typically in an approximately linear relationship within the normal operating range, with efficiency dropping off at very high currents.
• Forward Voltage vs. Forward Current:Shows the exponential I-V characteristic of the diode, which is crucial for determining the necessary drive voltage.
• Relative Luminous Intensity vs. Ambient Temperature:This curve will show the decrease in light output as junction temperature increases, a key consideration in high-temperature applications.
• Spectral Distribution:A graph showing the intensity of emitted light versus wavelength, centered at a 611 nm peak with a 17 nm half-width.

These curves enable designers to predict performance under non-standard conditions and optimize drive circuitry for improved efficiency and extended lifespan.

5. Mechanical and Packaging Information

The device uses a standard 10-pin Dual In-line Package (DIP). The character height is 0.4 inches (10.16 mm). The package featuresGray Panel with White Segments, yana ƙara bambanci lokacin da lambobin ba su kunna ba. Zanen girma ya ƙayyade duk mahimman girma, gami da faɗin gabaɗaya, tsayi, tazarar lambobi, da tazarar fil da tsayinsa. Tolerances yawanci ±0.25 mm ne, kuma tolerance na karkatar ƙarshen fil shine ±0.4 mm.Zanen da'irar cikiYana nuna a fili cewaAnode gama gariTsarin saiti, yana da filaye masu zaman kansu guda biyu na anode gama gari: ɗaya don lamba 1 (fil 9), ɗaya kuma don lamba 2 (fil 4). Wannan yana ba da damar yin multiplexing akan lambobi biyu.

6. Pin Connection and Circuit Configuration

Tsarin fil yana kamar haka: Fil 1: Cathode C, Fil 2: Cathode D.P. (decimal point), Fil 3: Cathode E, Fil 4: Anode gama gari (Lamba 2), Fil 5: Cathode D, Fil 6: Cathode F, Fil 7: Cathode G, Fil 8: Cathode B, Fil 9: Anode gama gari (Lamba 1), Fil 10: Cathode A. An haɗa ma'aunin goma na dama. Tsarin anode gama gari yana nufin don kunna wani ɓangaren lamba, dole ne a tura filin cathode ɗinsa zuwa ƙananan matakan lantarki (ƙasa ko haɗe zuwa mashigar ɗaukar ƙarfi), yayin da filin anode gama gari na lambar sa ake turawa zuwa babban matakin lantarki (ta hanyar resistor mai iyakancewar ƙarfi zuwa VCC). Wannan tsari ya dace sosai don turawa multiplexing, yana rage adadin filayen I/O na microcontroller da ake buƙata.

7. Soldering and Assembly Guidelines

Jagora mafi mahimmanci shine yanayin walda:Maximum 260°C for 3 seconds, measured 1/16 inch (approximately 1.6 mm) below the mounting plane.. This is a standard lead-free reflow soldering profile parameter. During this process, care must be taken to prevent the LED display body from exceeding its maximum rated temperature. Standard ESD (Electrostatic Discharge) precautions should be followed during handling. For cleaning, use methods compatible with plastic LED packages; avoid ultrasonic cleaning which may damage internal bond wires.

8. Shawarar Aikace-aikace

8.1 Yanayin Aikace-aikace na Al'ada

This display is suitable for applications requiring clear, medium-sized numeric readouts. Examples include: digital multimeters, frequency counters, power supply units, process control indicators, medical equipment displays, automotive aftermarket gauges, and point-of-sale terminal displays. Its wide temperature range makes it suitable for both indoor and protected outdoor equipment.

8.2 La'akari da Zane

• Current Limiting:External current-limiting resistors must be used for each segment cathode or common anode. The resistor value is calculated using the formula R = (Vcc - Vf) / If, where Vf is the forward voltage (use the maximum value for worst-case current calculation) and If is the desired forward current (e.g., 20mA).
• Multiplexed Driving:要驱动两个数字，微控制器可以交替使能数字1（引脚9为高电平）和数字2（引脚4为高电平），同时在引脚1-3、5-8、10上输出相应的段码阴极图案。刷新率必须足够高（通常>60Hz）以避免可见闪烁。
• Power Consumption:Ensure that the continuous current per segment does not exceed the derated limit at the maximum expected ambient temperature.
• Viewing Angle:The wide viewing angle allows for flexible mounting positions, but contrast is optimal when viewed head-on.

9. Kwatancen Fasaha da Bambance-bambance

The primary differentiation of the LTD-4608KF lies in its use ofAlInGaPTechnology. Compared to traditionalGaAsP (Gallium Arsenide Phosphide)red or yellow LEDs, AlInGaP offers significantly higher luminous efficiency, thereby achieving higher brightness at the same drive current. It also provides better temperature stability and a longer operational lifespan. Compared to newer,InGaN (Indium Gallium Nitride)-based white or blue LEDs used with color filters, AlInGaP yellow-orange provides a pure, saturated color without the complexity and efficiency loss of a phosphor conversion layer. Its specific yellow-orange hue (605-611 nm) is often chosen for its high visual impact and uniqueness.

10. Tambayoyin da ake yawan yi (bisa sigogin fasaha)

Q: Can I drive this display directly from a 5V microcontroller pin?
A: No. A current-limiting resistor must be used. For a 5V supply and a Vf of 2.6V at 20mA, the resistor value should be (5V - 2.6V) / 0.02A = 120 ohms. A standard 120Ω resistor is suitable.

Q: What is the purpose of setting up two separate common anode pins?
A: It supports multiplexing. By lighting up one digit at a time very quickly and displaying the correct number on it, you can control two digits with only 8 segment lines (7 segments + decimal point) and 2 digit control lines, instead of 16 lines (8 per digit). This saves microcontroller I/O.

Q: The luminous intensity range is very wide (27520 to 44000 µcd). How to ensure consistent brightness?
A: Specify a tighter luminous intensity bin when ordering. Manufacturers often offer parts sorted into specific intensity ranges (bins). Consult the manufacturer's full binning documentation.

Q: Is this display suitable for outdoor use in direct sunlight?
A: While it has high brightness and a wide temperature range, direct sunlight can be extremely intense (over 100,000 lux). The display's contrast may be washed out. For sunlight readability, displays with even higher brightness or specific optical filters are typically required.

11. Ayyukan ƙira da amfani na ainihi

Case: Designing a simple digital voltmeter readout.A designer is building a 0-20V DC voltmeter using a microcontroller with an ADC. The LTD-4608KF is chosen for its clarity and ease of interfacing. The microcontroller has 10 available I/O pins. The designer connects the 8 cathode pins (A-G and DP) to 8 microcontroller pins configured as outputs. The two common anode pins are connected to two other microcontroller pins via small NPN transistors (e.g., 2N3904) to handle the total segment current for each digit. The base of each transistor is driven by a microcontroller pin through a base resistor. The firmware is written to: 1) Read the ADC value and convert it into two BCD digits. 2) Look up the 7-segment pattern for each digit. 3) In a fast loop, turn on the transistor for digit 1, output the segment pattern for digit 1 to the cathode pins, wait a very short time, turn off digit 1, and then repeat the process for digit 2. This multiplexing scheme creates a stable, flicker-free two-digit reading using only 10 I/O pins.

12. Gabatarwar ka'idoji

A seven-segment display is a component composed of light-emitting diodes (LEDs) arranged in the shape of an "8". Each of the seven segments (labeled A through G) is an independent LED. By selectively illuminating specific combinations of these segments, all decimal digits (0-9) and some letters can be formed. The LTD-4608KF contains two such digit components in one package. The AlInGaP LED chip operates based on the principle of electroluminescence in direct bandgap semiconductors. When a forward voltage is applied across the p-n junction, electrons and holes recombine, releasing energy in the form of photons. The specific composition of the AlInGaP alloy determines the bandgap energy, thereby determining the wavelength (color) of the emitted light, which is yellow-orange in this case.

13. Hanyoyin ci gaba

While discrete seven-segment LED displays remain relevant in specific applications, the overall trend in display technology is moving towards integrated solutions. These include:
Higher Integration:Modules with built-in driver ICs, controllers, and even serial interfaces (I2C, SPI) are becoming common, simplifying microcontroller design.
Alternative Technologies:For larger or more complex displays, OLED (Organic Light-Emitting Diode) and high-brightness LCDs with LED backlighting are often preferred due to their flexibility in displaying graphics and custom characters.
Miniaturization and Efficiency:The continuous advancement of LED chip technology steadily improves luminous efficacy (lumens per watt), enabling displays to be brighter at lower power consumption or to achieve further miniaturization. However, for simple, robust, and low-cost numeric indication in industrial and instrumentation environments, discrete LED seven-segment displays like the LTD-4608KF remain a reliable and effective choice.