LTE-3371T Infrared Emitter Datasheet - High Power 940nm - Forward Voltage 1.6V - 150mW - Clear Package - Technical Documentation

1. Product Overview

The LTE-3371T is a high-performance infrared emitter, specifically designed for applications requiring robust optical output and stable operation under demanding electrical conditions. Its core design philosophy is to deliver high radiant power while maintaining a low forward voltage, enabling efficient operation in both continuous and pulsed drive schemes. The device emits at a peak wavelength of 940 nm, which falls within the spectrum invisible to the human eye, making it ideally suited for applications such as night vision systems, remote controls, and optical sensors where detection by the human eye is undesirable.

The transmitter employs a transparent package to maximize light extraction efficiency and provide a wide viewing angle, ensuring uniform radiation patterns. This product is particularly suitable for industrial, automotive, and consumer electronics applications, which require consistent performance across a wide temperature range and current variations.

2. Bincike mai zurfi na sigogi na fasaha

This section provides a detailed and objective interpretation of the key electrical and optical parameters defined in the datasheet, explaining their significance for design engineers.

2.1 Absolute Maximum Ratings

These ratings define the stress limits that may cause permanent damage to the device and are not applicable under normal operating conditions.

• Power Dissipation (150 mW):This is the maximum power the device can dissipate as heat at an ambient temperature (T_A) of 25°C. Exceeding this limit risks overheating and damaging the semiconductor junction, leading to accelerated aging or catastrophic failure. Designers must ensure the thermal management of the PCB and surrounding environment keeps the junction temperature within a safe range, especially when operating under high continuous current.
• Peak Forward Current (2 A @ 300pps, 10μs pulse):This device can withstand very high instantaneous current, but only under specific pulse conditions (300 pulses per second, each with a 10-microsecond width). This rating is crucial for applications like infrared communication, which transmit data in short, high-power bursts. The average current during pulsed operation must still be kept within the continuous current and power dissipation limits.
• Continuous Forward Current (100 mA):The maximum DC current that can pass through the device indefinitely under specified conditions. Operating near this limit requires excellent heat dissipation measures.
• Reverse Voltage (5 V):The maximum voltage that can be applied in the reverse bias direction. Exceeding this value may lead to breakdown and immediate failure. Circuit protection, such as series resistors or parallel protection diodes, is often required.
• Operating and Storage Temperature Range:This device is rated for industrial-grade temperature ranges (Operating: -40°C to +85°C, Storage: -55°C to +100°C), indicating its suitability for harsh environments.
• Pin Soldering Temperature (260°C for 5 seconds):Provides guidance for wave soldering or hand soldering, specifying the maximum temperature and duration that pins can withstand at 1.6mm from the package body.

2.2 Halaye na Lantarki da Na'urar gani

These parameters are measured under standard test conditions (T_A=25°C) and define the device's performance.

• Aperture Irradiance (E_e) and Radiant Intensity (I_E):This is the core optical output parameter. E_emeasures power density (mW/cm²), while I_Emeasures power emitted per unit solid angle (mW/sr). Both are tested at a forward current (I_F) of 20mA. The values are graded (see Section 3), with typical ranges from 0.64-1.20 mW/cm² (Grade B) to 4.0 mW/cm² (Grade G). Higher grades provide significantly stronger optical power.
• Peak Emission Wavelength (λ_Peak):The nominal value is 940 nm. This wavelength can be efficiently detected by silicon photodiodes and is essentially invisible, making it ideal for covert illumination.
• Spectral Line Half-Width (Δλ):Approximately 50 nm. This specifies the spectral bandwidth; a narrower width indicates better monochromaticity of the light source, which can be important for filtering out ambient light in sensing applications.
• Forward Voltage (V_F):A key electrical efficiency parameter. Typical V_F1.6V at 50mA, 2.1V at 250mA. The relatively low V_F(Min 1.65V, Max 2.1V @ 250mA) is a standout feature, reducing power loss and heat generation in the LED itself.
• Reverse Current (I_R):Maximum 100 μA at a Reverse Voltage (V_R) of 5V. Low leakage current is ideal.
• Viewing Angle (2θ_1/2):40 degrees (minimum). This is the full angle at which the radiant intensity drops to half of its maximum (on-axis) value. The wide 40° viewing angle provides broad, uniform illumination, suitable for applications like proximity sensors or area lighting.

3. Bayani na Tsarin Rarrabawa

LTE-3371T employs a strict binning system for its radiant output, ranging from Bin B to Bin G. This system ensures consistency within production lots and allows designers to select devices that meet their specific optical power requirements.

• Optical Power Binning:The primary binning parameters are radiant intensity (I_E) and aperture irradiance (E_e). For example, a Bin D device typically has an I_Erange of 8.42-16.84 mW/sr, while a Bin G device is rated at 30 mW/sr (minimum). Bin G has no specified upper limit, indicating it represents the highest-performing units in production.
• Design Implications:When designing a system, specifying the bin code is crucial for achieving predictable performance. Using a lower bin device may require higher drive current to achieve the same optical output as a higher bin, impacting system efficiency and thermal design. For cost-sensitive applications, lower bins may suffice, while high-performance systems require Bin E, F, or G.
• Wavelength Consistency:The datasheet specifies a single peak wavelength (940nm) without binning, indicating tight control over the epitaxial growth process, resulting in consistent spectral characteristics across all bins.

4. Bincike kan Lankwilar Aiki

The provided graphs offer key insights into the device's behavior under non-standard conditions.

4.1 Taswirar Rarraba Bakan (Figure 1)

This curve confirms the peak emission at 940nm and a spectral half-width of approximately 50nm. Its shape is typical for AlGaAs-based infrared emitters. The curve shows minimal emission within the visible spectrum, confirming its covert nature.

4.2 Taswirar Dangantakar Ƙarfin Kwarara da Yanayin Muhalli (Figure 2)

Wannan lankwasa rage ƙarfi yana da mahimmanci ga sarrafa zafi. Yana nuna matsakaicin ƙarfin gaba mai ci gaba da aka yarda yana raguwa yayin da yanayin zafi ya tashi. A 85°C, matsakaicin ƙarfin da aka yarda ya yi ƙasa sosai da ƙimar 100mA a 25°C. Dole ne masu zane su yi amfani da wannan zane don tantance amincin aikin su a cikin mafi munin yanayin zafi.

4.3 Taswirar Dangantakar Ƙarfin Kwarara da Ƙarfin Ƙarfafawa (Figure 3)

Wannan daidaitaccen lankwasa I-V ne, yana nuna alaƙar ma'auni. Wannan lankwasa yana ba masu zane damar kimanta raguwar ƙarfin lantarki da amfani da wutar lantarki (V_F* I_F) a kowane ƙarfin aiki da aka ba, wanda ke da mahimmanci don zaɓar madaidaicin resistor mai iyakancewa ko kewayon tuƙi.

4.4 Taswirar Dangantakar Ƙarfin Haske da Yanayin Zafi (Hoto 4) da Ƙarfinsa (Hoto 5)

Hoto na 4 yana nuna fitowar gani tana raguwa yayin da zafin jiki ya tashi (ma'auni mara kyau na zafin jiki), wannan halayyar LED ce ta gama gari. Hoto na 5 yana nuna fitarwa yana ƙaruwa da ƙarfi fiye da layi. Kodayake fitarwa yana ƙaruwa tare da ƙarfin gaba, a cikin ƙarfin gaba mai tsanani, yawanci yawan aiki yana raguwa saboda ƙarin zafi. Waɗannan lankwasai suna taimakawa wajen daidaita ma'auni tsakanin ƙarfin fitarwa, inganci, da rayuwar na'urar.

4.5 Tsarin Tsarin Haske (Hoto 6)

This polar plot visually represents the viewing angle. The concentric circles indicate relative intensity (from 0 to 1.0). The plot confirms a broad, approximately Lambertian (cosine) emission pattern, with intensity dropping to half of its peak value at approximately ±20° from the central axis (total 40°).

5. Bayanin Injiniya da Kunshewa

The device uses a standard through-hole package with a transparent resin lens. Key dimensional specifications in the datasheet include:

• All dimensions are in millimeters. Unless otherwise specified, the standard tolerance is ±0.25mm.
• A maximum resin protrusion of 1.5mm below the flange is permitted, which must be considered for PCB spacing and cleaning.
• The lead pitch is measured where the leads extend from the package body, which is critical for PCB pad design.
• The package includes a flange, which aids in mechanical stability during soldering and provides a visual and physical reference for orientation.

Polarity Identification:The datasheet implies standard LED polarity (typically, the longer pin is the anode). However, designers should always refer to the specific package drawing to confirm the anode/cathode marking, usually indicated by a flat side or notch on the package flange.

6. Jagorar Walda da Haɗawa

Adherence to these guidelines is critical for reliability.

• Soldering:Absolute maximum ratings specify a pin soldering temperature of 260°C for a maximum of 5 seconds, measured at a point 1.6mm from the package body. This is compatible with standard wave soldering or hand soldering processes. For reflow soldering, a temperature profile with a peak temperature below 260°C and limited time above the liquidus should be used to prevent thermal damage to the plastic package or internal die bonds.
• Operation:Standard ESD (Electrostatic Discharge) precautions should be observed, as semiconductor junctions can be damaged by static electricity.
• Cleaning:Transparent resin packages may be sensitive to certain strong solvents. If post-solder cleaning is required, compatibility should be checked.
• Storage:Devices should be stored within the specified temperature range (-55°C to +100°C) in a low-humidity, non-corrosive environment. For moisture-sensitive devices, they should be kept in a sealed bag with desiccant if not baked before use.

7. Shawarwari na Aikace-aikace

7.1 Yanayin Aikace-aikace na Al'ada

• CCTV/Night Vision Infrared Illumination:These emitter arrays can be used to provide covert illumination for security cameras equipped with infrared-sensitive sensors.
• Proximity and Presence Detection:Paired with a photodetector, this emitter can be used for non-contact switching, object detection, and liquid level sensing.
• Optical Data Transmission:Due to its high pulse current capability, it is suitable for short-range, low-data-rate infrared communication links (e.g., remote controls, industrial telemetry).
• Industrial Automation:Digunakan untuk encoder optik, penghitungan objek pada jalur produksi, dan sensor berkas cahaya terputus.

7.2 Tunani na Ƙira

• Penggerak Arus:LED adalah perangkat yang digerakkan oleh arus. Selalu gunakan sumber arus konstan atau resistor pembatas arus yang disambung seri dengan sumber tegangan. Rumus untuk menghitung nilai resistansi adalah R = (V_{Catu Daya}- V_F) / I_F. Gunakan V_FValue, to ensure that the current does not exceed the desired value under all conditions.
• Thermal Management:对于高电流（例如，>50mA）下的连续工作，需考虑功耗（P_D= V_F* I_F) must be considered. Ensure the PCB has sufficient copper area (thermal pad) to conduct heat away from the pin. Refer to the derating curve (Figure 2).
• Optical Design:A wide viewing angle may require a lens or reflector to collimate the light for long-distance applications. For diffuse illumination, a wide viewing angle is beneficial.
• Electrical Protection:Consider connecting a small-value resistor in series with the LED to limit inrush current. If the drive circuit may generate reverse voltage, connect a reverse-biased protection diode in parallel across the LED.

8. Kwatancen Fasaha da Bambanci

Based on its specifications, the LTE-3371T demonstrates differentiation in the following key areas:

• High Current Capability:For a device in this package style, a 2A peak pulse current rating is very high, enabling very bright, short-duration pulses, making it well-suited for long-range sensing or communication.
• Low Forward Voltage:For a high-power infrared emitter, a typical V_Fof 1.6V at 50mA is relatively low. Compared to devices with higher V_F.
• Compared to devices, this directly translates to higher electrical efficiency and less heat waste at a given optical output.Wide Viewing Angle with Transparent Encapsulation:
• This combination provides uniform, efficient light output without the diffusing effect of tinted encapsulation, maximizing total luminous flux.Industrial-Grade Temperature Rating:

An operating range of -40°C to +85°C makes it suitable for automotive and outdoor applications where standard commercial-grade components may fail.

9. Frequently Asked Questions (Based on Technical Parameters)

9.1 Can I drive this LED directly with a 5V microcontroller pin?A'a, ba za a iya tuƙa kai tsaye ba._FMicrocontroller GPIO fil ɗin yawanci kawai zai iya samar da ƙayyadaddun ƙarfin lantarki (misali, 20-40mA), kuma ba zai iya samar da buƙatun ƙarfin lantarki na ƙarfi ba. Dole ne ku yi amfani da kewaye na tuƙa. Hanya mafi sauƙi ita ce haɗa resistor a jere: don 5V wutar lantarki da manufa I_Fshine 50mA, yi amfani da matsakaicin V²1.6V, R = (5V - 1.6V) / 0.05A = 68Ω. Ƙimar wutar lantarki na resistor ya kamata ya zama P = I²² * R = (0.05)² * 68 = 0.17W, don haka resistor 1/4W ya isa.

9.2 What is the difference between radiant intensity (mW/sr) and aperture irradiance (mW/cm²)?

Ƙarfin haske (I_E)) shine ma'auni na yadda tushen haske a wani takamaiman shugabanci (yawanci axial) yakekowace raka'a mai tsayifitar da yawan wutar haske. Yana bayyana "maida hankali" na hasken.Aperture irradiance (E_e)) is the power density (power per unit area) measured at a specific distance, typically on the effective area of a detector placed perpendicular to the beam. For a given LED, they are related, but I_Eis more fundamental for characterizing the light source itself, while E_eis more practical for calculating the signal on a specific detector.

9.3 Why does the optical output decrease with increasing temperature (Figure 4)?

This is due to several semiconductor physics phenomena. Primarily, increased temperature raises the probability of non-radiative recombination events within the LED's active region. The energy of recombining electron-hole pairs is converted into lattice vibrations (heat) instead of generating photons (light). This reduces the device's internal quantum efficiency. Additionally, the peak emission wavelength may shift slightly with temperature.

10. Nazarin ainihin ƙirar ƙira

Scenario:Design a short-range (1 meter) infrared proximity sensor for detecting the presence of objects.

• Transmitter Drive:Use LTE-3371T (D grade for good output). Drive via MOSFET switching from a 5V supply with 100mA, 1ms pulses, once every 100ms (1% duty cycle). Average current is 1mA, well within limits. A series resistor is needed, with a value of (5V - 2.1V_Maximum)/0.1A ≈ 30Ω.
• Detector:Use a silicon phototransistor or photodiode with a spectral response peak near 940nm. Place it a few centimeters away from the transmitter to avoid direct coupling.
• Optics:LTE-3371T's 40° wide viewing angle is very suitable for creating a diffuse "light curtain" in front of the sensor. For this short-range, diffuse application, no additional lens is required.
• Signal Processing:The detector's output will show a baseline level (ambient light), and a spike will appear when the emitted pulse is reflected back from a nearby object. Synchronous detection circuitry (which looks for the signal only during the 1ms pulse) can greatly improve immunity to ambient light noise.

11. Ayyukan aiki

LTE-3371T is a semiconductor light-emitting diode. Its operating principle is based on electroluminescence in a direct bandgap semiconductor material (likely aluminum gallium arsenide). When a forward voltage is applied, electrons are injected from the n-type region and holes are injected from the p-type region into the active region (p-n junction). These carriers recombine, releasing energy. In direct bandgap materials like AlGaAs, this energy is released primarily as photons (light). The specific wavelength of 940nm is determined by the bandgap energy of the semiconductor material used in the active layer, which is engineered during the material's epitaxial growth. The transparent epoxy package is used to protect the semiconductor chip, provide mechanical support for the leads, and act as a lens to shape the emitted light output.

12. Trends na fasaha

Infrared emitter technology is evolving along with broader optoelectronic trends. Key development areas include:

• Higher Power Density and Efficiency:Continuous improvements in epitaxial growth and chip design aim to extract more optical power from a given chip size while minimizing forward voltage, directly enhancing lumens per watt (or electrical-to-optical power) efficiency.
• Advanced Packaging:Trends include surface-mount device packages with improved thermal performance (e.g., chip-on-board designs), allowing higher continuous operating currents and better reliability. There is also development of packages with integrated lenses or diffusers for specific beam patterns.
• Multi-Wavelength and VCSEL:For sensing applications such as time-of-flight and LiDAR, Vertical-Cavity Surface-Emitting Lasers (VCSELs) are growing significantly. Compared to traditional LED emitters (e.g., LTE-3371T), VCSELs offer narrower spectral width, faster modulation speed, and lower divergence angle. However, for many applications, LEDs remain highly cost-effective and reliable.
• Integration with Drivers:There is a trend toward smarter components, with some emitters integrating simple driver circuits or protection features (such as ESD diodes) within the package.

LTE-3371T yana mai da hankali kan ƙarfin bugun jini mai girma, ƙananan V_Fda tsari mai ƙarfi, yana wakiltar cikakkiyar mafita mai aminci a cikin wannan ci gaban, musamman don aikace-aikacen da ke buƙatar hasken infrared mai inganci mai tsada.