LTP-3786JD-03 LED Display Datasheet - 0.54-inch Digit Height - Hyper Red - 2.6V Forward Voltage - English Technical Document

1. Product Overview

LTP-3786JD-03 o jẹ iṣafihan alfanumeriki 14-ẹya, oni-nọmba meji ti a ṣe apẹrẹ fun awọn ohun elo ti nwọle si afihan kọọkan kedere. O ni giga nọmba ti 0.54 inṣi (13.8 mm), eyi ti o mu ki o yẹ fun awọn iwe-ka iwọn aarin ninu ọpọlọpọ ẹrọ itanna. Ẹrọ naa nlo awọn chipi LED AlInGaP (Aluminum Indium Gallium Phosphide) Hyper Red ti a ṣe lori substrate GaAs, ti o pese ipilẹṣẹ iṣafihan kan pato. Iṣafihan naa ni oju awọ ehu funfun pẹlu awọn ẹya funfun, ti o mu idaniloju ati iṣe-ka pọ si.

1.1 Awọn ẹya Ipilẹ ati Awọn Anfani

• Iri Kọọkan: Continuous, uniform segments contribute to excellent character definition and appearance.
• Optical Performance: High brightness and high contrast ratio ensure visibility in various lighting conditions.
• Viewing Angle: A wide viewing angle allows the display to be read from different positions.
• Power Efficiency: Low power requirement, typical of LED technology.
• Reliability: Solid-state construction offers long operational life and resistance to shock and vibration.
• Consistency: Devices are categorized (binned) for luminous intensity, aiding in achieving uniform brightness across multiple units in an assembly.

1.2 Target Applications

This display is intended for use in ordinary electronic equipment. This includes, but is not limited to, office automation equipment, communication devices, household appliances, instrumentation panels, and consumer electronics where clear numeric and limited alphabetic readouts are needed.

2. Technical Specifications Deep Dive

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. Operation should be maintained within these limits.

• Power Dissipation per Chip: 70 mW
• Peak Forward Current per Chip: 90 mA (under pulsed conditions: 1/10 duty cycle, 0.1 ms pulse width)
• Continuous Forward Current per Chip: 25 mA at 25°C. A derating factor of 0.33 mA/°C applies above 25°C.
• Reverse Voltage per Chip: 5 V
• Operating & Storage Temperature Range: -35°C to +85°C
• Solder Condition: 260°C for 3 seconds, with the solder point at least 1/16 inch (≈1.6 mm) below the device's seating plane.

2.2 Electrical & Optical Characteristics (Ta=25°C)

These are the typical performance parameters under specified test conditions.

• Average Luminous Intensity (I_V): 200-520 µcd (microcandelas) at a forward current (I_F) of 1 mA. Measured with a filter approximating the CIE photopic eye-response curve.
• Peak Emission Wavelength (λ_p): 650 nm at I_F=20 mA.
• Dominant Wavelength (λ_d): 639 nm at I_F=20 mA, with a tolerance of ±1 nm. This defines the perceived color.
• Spectral Line Half-Width (Δλ): 20 nm at I_F=20 mA, indicating the spectral purity.
• Forward Voltage per Segment (V_F): 2.1V to 2.6V at I_F=20 mA. Tolerance is ±0.1V.
• Reverse Current per Segment (I_R): Maximum 100 µA at a reverse voltage (V_R) of 5V.
• Luminous Intensity Matching Ratio (I_V-m): Maximum 2:1 ratio between segments at I_F=1 mA, ensuring brightness uniformity.
• Crosstalk: ≤ 2.5%, minimizing unwanted illumination of non-selected segments.

3. Mechanical and Package Information

3.1 Package Dimensions

The display is provided in a standard dual-digit package with 18 pins. Key dimensional notes include:

• All dimensions are in millimeters (mm).
• General tolerance is ±0.25 mm unless otherwise specified.
• Pin tip shift tolerance is ±0.4 mm.
• Recommended PCB hole diameter for the pins is 1.0 mm.
• Quality criteria are defined for foreign material (≤10 mil), ink contamination (≤20 mil), bubbles in segments (≤10 mil), and reflector bending (≤1% of length).

3.2 Pin Configuration and Internal Circuit

The device features a common anode configuration. There are two common anode pins: one for Character 1 (pin 16) and one for Character 2 (pin 11). All other pins (except pin 3, which is No Connection) are cathodes for individual segments (A through P, and D.P. for the decimal point). The internal circuit diagram shows the independent LED chips for each segment, connected to their respective common anodes. This structure allows multiplexing for driving the two digits.

4. Application Guidelines and Cautions

4.1 Tunani na Zane da Amfani

• Iyakokin Aikace-aikace: Yana dace da na'urorin lantarki na yau da kullun. Ba a ba da shawarar don aikace-aikacen mahimmanci na aminci (jirgin sama, tallafin rayuwar likita, da sauransu) ba tare da tuntubar farko ba.
• Zane na'urar tuƙi:
  • Tuƙi na Madaidaicin Halin Yanzu: Highly recommended to maintain consistent luminous intensity and color.
  • Voltage Range: The circuit must accommodate the full V_F range (2.1V-2.6V) to ensure the desired current is delivered under all conditions.
  • Protection: The circuit should protect against reverse voltages and transient voltage spikes during power cycling.
  • Thermal Management: Operating current must be derated based on the maximum ambient temperature to prevent light degradation or failure.
• Avoid Reverse Bias: Can cause metal migration, increasing leakage current or causing shorts.
• Environmental: Avoid rapid temperature changes in humid environments to prevent condensation on the display.
• Mechanical Handling: Do not apply abnormal force to the display body during assembly.
• For Multi-Displays: Use displays from the same luminous intensity bin (BIN) to avoid uneven brightness (hue) across an assembly.

4.2 Storage and Handling Conditions

• Standard Storage (in original packaging): Temperature: 5°C to 30°C. Humidity: Below 60% RH. Long-term storage outside these conditions can lead to pin oxidation.
• Post-Open Storage (for SMD types, reference): If the moisture barrier bag is opened, the device should be used within 168 hours (MSL Level 3) under the same temperature/humidity conditions.
• Baking: If an unsealed package has been stored for over 6 months, baking at 60°C for 48 hours is recommended before assembly, which should be completed within one week.

Performance Curves and Characteristics Analysis

The datasheet references typical performance curves (though not displayed in the provided text). These curves are crucial for design and typically include:

• Forward Current vs. Forward Voltage (I-V Curve): Yana nuna alakar da ba ta layi ba, mai mahimmanci don zaɓin resistors masu iyakancewar halin yanzu ko ƙirar direbobi masu tsayayyen halin yanzu.
• Ƙarfin Haskakawa da Halin Yanzu na Gaba: Yana nuna yadda fitowar haske ke ƙaruwa tare da halin yanzu, yana taimakawa wajen daidaita haske da binciken inganci.
• Ƙarfin Haskakawa da Yanayin Yanayi na Kewayawa: Shows the derating of light output as temperature rises, critical for thermal design in high-temperature environments.
• Spectral Distribution: A graph of relative intensity vs. wavelength, confirming the dominant and peak wavelengths and the spectral half-width.

Designers should consult the full datasheet graphs to understand these relationships quantitatively for their specific operating conditions.

6. Technical Comparison and Differentiation

The LTP-3786JD-03 differentiates itself through several key aspects:

• Fasahar Chip: Yana amfani da AlInGaP Hyper Red chips, waɗanda gabaɗaya ke ba da ingantacciyar inganci da ingantaccen kwanciyar hankali na zafi idan aka kwatanta da tsofaffin fasahohin GaAsP ko GaP don launukan ja/lemu.
• Ƙirar Gani: U fesi efuefue efuefue ma u paepae hinehina ua faataa mo le eseesega maualuga, faaleleia atili le faitau pe a faatusatusa i ata faaaliali ua uliuli pe ua faasalalauina vaega.
• Quality Control: O le faʻamatalaga o tapulaʻa faʻapitoa mo faʻaletonu vaega (pupa, faʻaleagaina) ma le faʻavasegaina mo le malosi malamalama (BINning) e faʻaalia ai le taulaʻi i le tutusa o le malamalama ma le lelei.
• Package: The 18-pin, through-hole design with separate common anodes for each digit provides flexibility in multiplexing drive circuits.

7. Frequently Asked Questions (FAQs)

7.1 How do I drive this display?

Use a multiplexing technique. Sequentially enable one common anode (digit) at a time while applying the correct cathode pattern for the desired segments on that digit. The cycle must be fast enough to avoid flicker (typically >60 Hz). A constant current driver per segment or a current-limited supply is recommended.

7.2 What is the purpose of the intensity BIN code?

The BIN code groups displays based on their measured luminous intensity at a standard test current. Using displays from the same BIN in a multi-unit application ensures uniform brightness across all digits, preventing a patchy appearance.

7.3 Can I use a simple resistor to limit current?

Yes, for simple applications. Calculate the resistor value using R = (V_supply - V_F) / I_F. Use the maximum V_F from the datasheet (2.6V) to ensure the minimum current is met under worst-case conditions. However, for best consistency across segments and temperatures, a constant current circuit is superior.

7.4 Why is reverse voltage protection important?

Applying a reverse bias beyond the absolute maximum rating (5V) can cause immediate damage. Even smaller reverse voltages, if sustained or repetitive (e.g., from inductive kickback in a circuit), can degrade the LED over time through electromigration, leading to increased leakage or failure.

8. Practical Application Example

Scenario: Designing a simple two-digit counter.

1. Microcontroller Interface: Connect the two common anode pins (11, 16) to two GPIO pins configured as current-sourcing outputs. Connect the 16 segment cathode pins to GPIO pins configured as current-sinking outputs, possibly through transistors or a driver IC for higher current.
2. Current Limiting: Implement constant current sinks for each cathode line, set to 10-15 mA for a good balance of brightness and longevity, staying well below the 25 mA continuous rating.
3. Software: Create a look-up table mapping numbers 0-9 to the appropriate segment patterns (A-G). In the main loop, enable Digit 1, output the pattern for the tens place, wait 1-5 ms, disable Digit 1, enable Digit 2, output the pattern for the ones place, wait 1-5 ms, and repeat. This creates a stable, flicker-free display.
4. Thermal Consideration: If the enclosure might get hot (e.g., >50°C), consider reducing the drive current slightly using the derating factor (0.33 mA/°C above 25°C) to ensure reliability.

9. Operating Principle and Technology Trends

9.1 Basic Operating Principle

LED wani diode ne na semiconductor. Lokacin da aka yi amfani da ƙarfin lantarki na gaba wanda ya wuce bandgap dinsa, electrons da ramuka suna sake haɗuwa a cikin yanki mai aiki (AlInGaP Layer a wannan yanayin), suna sakin makamashi a cikin nau'in photons (haske). Takamaiman abun da ke cikin gawa na AlInGaP yana ƙayyade makamashin bandgap don haka kuma tsawon zango (launi) na hasken da aka fitar, wanda ke cikin bakan hyper-red na wannan na'urar. Tsarin sashi 14 yana ba da damar samar da lambobi da ƙayyadadden saitin haruffa ta hanyar haskaka haɗuwar sassan da aka zaɓa.

9.2 Industry Trends

Yayin da na'urorin nuni masu ramuka kamar LTP-3786JD-03 suke da muhimmanci ga ƙirƙira samfuri, gyara, da wasu aikace-aikacen masana'antu, babban yanayin fasahar nuni yana zuwa ga fakitin na'urar da ake haɗawa ta saman (SMD) don haɗawa ta atomatik da ƙanƙanta. Bugu da ƙari, akwai ci gaba da ƙoƙari don ingantaccen inganci (ƙarin lumens a kowace watt), wanda ga LED ja ya haɗa da inganta tsarin AlInGaP epitaxial da inganta fitowar haske daga guntu. Ga na'urorin nuni na haruffa da lambobi, allunan ɗigo-matrix sun zama gama gari yayin da suke ba da cikakken ikon haruffa da zane-zane, ko da yake na'urorin nuni masu rabe-rabe suna riƙe da fa'idodi a farashi, sauƙi, da bayyanawa don karatun lambobi na musamman.