LTR-1650D Phototransistor Datasheet - Package Size 5.0x4.0x3.2mm - Voltage 30V - Power 100mW - Dark Transparent Package - Technical Documentation

1. Product Overview

LTR-1650D is a silicon NPN phototransistor specifically designed for infrared detection applications. It features a low-cost, dark-transparent plastic package that effectively filters out visible light while transmitting infrared wavelengths (primarily around 940nm). An integrated lens focuses incident infrared radiation onto the transistor's active area, thereby enhancing the device's sensitivity. This component is designed to deliver reliable performance across a wide operating temperature range, making it suitable for various sensing and control systems.

2. Key Features and Core Advantages

• Wide Range Collector Current:This device offers multiple performance grades (A through F), with a wide selection range for the on-state collector current (IC(ON)), from a minimum of 0.2mA to over 9.6mA, allowing designers to choose the appropriate model based on specific sensitivity requirements.
• High Sensitivity Lens:Integrated epoxy lens increases the effective collection area of infrared light, improving signal-to-noise ratio and overall responsivity.
• Cost-effective plastic packaging:Uses standard, economical plastic housing, suitable for mass production and broad market applications.
• Special dark transparent packaging:The packaging material is treated with coloring to attenuate visible light, reduce interference from ambient light sources, and enhance performance in environments with fluctuating light conditions.

3. Uchambuzi wa kina wa Vigezo vya Kiufundi

3.1 Viwango vya Juu Kabisa

These ratings define the stress limits that may cause permanent damage to the device. Operation under these conditions is not guaranteed.

• Power Dissipation (P_D):At T_A=25°C, it is 100 mW. This is the maximum power the device can safely dissipate as heat.
• Collector-Emitter Voltage (V_CEO):30 V. The maximum voltage that can be applied between the collector and emitter terminals with the base open.
• Emitter-Collector Voltage (V_ECO):5 V. The maximum reverse voltage that can be applied between the emitter and collector.
• Operating Temperature Range (T_opr):-40°C to +85°C. The ambient temperature range over which the device is specified to operate.
• Storage Temperature Range (T_stg):-55°C to +100°C.
• Pin soldering temperature:For 5 seconds at 260°C, 1.6mm from the package body. This is critical for wave soldering or reflow soldering processes.

3.2 Electrical and Optical Characteristics (T_A=25°C)

The following parameters, tested under specific conditions, define the device's performance.

• Collector-Emitter Breakdown Voltage (V_(BR)CEO):30 V (min). At zero irradiance (E_C= 0 mW/cm²) and I_eTested under the condition of = 1mA.
• Emitter-collector breakdown voltage (V_(BR)ECO):5 V (minimum). Under no irradiance and I_ETested under the condition of = 100µA.
• Collector-Emitter Saturation Voltage (V_CE(SAT)):0.4 V (max). The voltage drop across the transistor when it is fully "on", tested under the condition of I_C= 100µA and E_e= 1 mW/cm². Low V_CE(SAT)is desirable for efficient switching operation.
• Rise time (T_r) na wakati wa kushuka (T_f):10 µs (kawaida). Vigezo hivi vya kasi ya kubadili kwenye V_CC=5V, I_C=1mA, R_L=1kΩ conditions. They determine the phototransistor's response speed to changes in light intensity.
• Collector dark current (I_CEO):100 nA (maximum). This is the device's current under complete darkness (E_e= 0 mW/cm²) and V_CELeakage current flowing through the collector under the condition of V_CE = 10V. Low dark current is crucial for a good signal-to-noise ratio in weak light detection.

3.3 On-state collector current (I_C(ON)) Grading System

LTR-1650D is classified into different grades based on its sensitivity, which is determined under standardized conditions (V_CE= 5V, E_e= 1 mW/cm², λ = 940nm) defined by the measured on-state collector current. This allows for precise selection based on application gain requirements.

• Grade A:0.2 - 0.6 mA
• Grade B:0.4 - 1.2 mA
• Daraja C:0.8 - 2.4 mA
• Daraja D:1.6 - 4.8 mA
• Daraja E:3.2 - 9.6 mA
• Grade F:6.4 mA (min)

Designers should consult the specific grade code when ordering to ensure the phototransistor meets the circuit's sensitivity and output current requirements.

4. Performance Curve Analysis

Mwongozo wa data hutoa mikunjo kadhaa ya sifa, inayoonyesha jinsi vigezo muhimu vinavyobadilika kulingana na hali ya mazingira na umeme.

4.1 Collector Dark Current vs. Ambient Temperature (Figure 1)

The curve shows that the collector dark current (I_CEO) increases exponentially with rising ambient temperature. This is a fundamental property of semiconductors, where thermally generated carriers become more prevalent. In high-temperature applications, this increased leakage current can become a significant noise source and must be considered in the design of the sensing amplifier's threshold.

4.2 Collector Power Dissipation vs. Ambient Temperature (Figure 2)

This graph depicts the derating of maximum allowable power dissipation with increasing ambient temperature. At 25°C, the device can withstand 100mW. As temperature rises, this rating decreases linearly. For reliable operation above 25°C, the actual dissipated power (V_CE* I_C) must remain below the derating curve. This is crucial to prevent thermal runaway and ensure long-term reliability.

4.3 Rise/Fall Time vs. Load Resistance (Figure 3)

This curve illustrates the trade-off between switching speed and load resistance (R_L). Rise and fall times increase with larger load resistance. This is because a larger R_Lforms a larger RC time constant with the phototransistor's junction capacitance. For applications requiring fast pulse detection, a smaller load resistor should be used, albeit at the cost of reduced output voltage swing.

4.4 Relative Collector Current vs. Irradiance (Figure 4)

The figure shows the relationship between incident infrared irradiance (E_e) and the generated collector current. The response is typically linear within a certain range, which is ideal for analog light sensing applications. The slope of the line represents the responsivity of the device. Understanding this characteristic is crucial for calibrating the sensor output to specific light intensity levels.

4.5 Sensitivity Pattern (Figure 5)

This polar plot illustrates the angular dependence of the phototransistor's sensitivity. Sensitivity is typically highest when infrared light is incident perpendicular to the lens (0°). It decreases as the angle of incidence increases. This characteristic is crucial for designing optical paths in applications, such as ensuring proper alignment in slot-type interrupters or defining the field of view for proximity sensors.

5. Mechanical and Packaging Information

5.1 Package Dimensions

The device is housed in a standard 3mm (T-1) radial leaded package. Key dimensions include:

• Package body diameter: approximately 5.0mm.
• Urefu wa kifuniko: takriban 3.2mm (bila pini).
• Umbali kati ya pini: hupimwa pale pini zinapotoka kwenye kifuniko, kwa kawaida ni 2.54mm (0.1").
• Upeo wa juu wa mfinyano wa mfupa chini ya flange unaruhusiwa kuwa 1.5mm.

Kumbuka:Isipokuwa imebainishwa vinginevyo, vipimo vyote viko kwenye milimita, na uvumilivu wa kawaida ni ±0.25mm. Wabunifu lazima watazamie michoro ya kina ya mitambo kwa ajili ya upangaji sahihi wa pedi na mipango ya uwekaji.

5.2 Polarity Identification

A phototransistor has two pins: the collector and the emitter. The longer pin is usually the collector. There may be a flat side or other marking on the package near the collector pin. Correct polarity is crucial for the proper operation of the circuit and the application of the correct bias voltage.

6. Mwongozo wa Uchomeleaji na Usanikishaji

• Uchomeaji kwa Mkono:Tumia chuma cha kuchomea chenye udhibiti wa joto. Punguza muda wa uchomeaji ili kuzuia uhamisho mwingi wa joto kwenye chip ya semiconductor.
• Uchomeaji wa Wimbi la Mafuta/Uchomeaji wa Kurudisha:Strictly adhere to the maximum ratings: 5 seconds at 260°C at a distance of 1.6mm from the package body. Exceeding these values may damage the internal wire bonds or the epoxy package.
• Cleaning:Use an appropriate solvent compatible with dark transparent epoxy. Avoid ultrasonic cleaning unless its safety for the package has been verified.
• Uhifadhi:Katika safu ya halijoto iliyowekwa ya -55°C hadi +100°C, hifadhi katika mazingira yaliyokauka na yasiyo na umeme tuli, ili kuzuia unyevunyevu (unaoweza kusababisha athari ya "popcorn" wakati wa kuunganishwa tena) na uharibifu wa kutokwa kwa umeme tuli.

7. Mapendekezo ya Matumizi na Mazingatio ya Ubunifu

7.1 Mazingira ya Kawaida ya Utumizi

• Object Detection and Interruption:Used for slot-type photoelectric switches (e.g., paper detection in printers, limit sensing in 3D printers).
• Uhisio wa Karibu:Inaunganishwa na LED ya infrared, inatumika kugundua vitu bila kugusa.
• Kikokotoo:Kutambua muundo kwenye diski inayozunguka, kwa ajili ya kupima kasi au msimamo.
• Udhibiti wa viwanda:Inatumika katika vifaa vya usanidi vinavyohitaji kupinga usumbufu wa mwanga wa mazingira.
• Elektroniki za watumiaji:Infrared Remote Control Receiver (although often used with dedicated ICs, phototransistors can form the front end).

7.2 Mambo Muhimu ya Kukusudiwa

• Bias Circuit:Transista ya Mwanga inaweza kutumika katika usanidi wa swichi (kawaida ya emitter) au mfuasi (emitter follower). Usanidi wa kawaida ya emitter hutoa faida ya voltage, na hutumiwa kwa kawaida katika swichi za dijiti. Inahitaji upinzani wa kuvuta juu (R_L).
• Chagua R_L:Uchaguzi wa thamani ya upinzani wa mzigo R unahusisha usawazishaji. Kwa mkondo wa mwanga uliopewa, R kubwa_LInaweza kutoa mwingilio mkubwa wa voltage, lakini itapunguza kasi ya kubadili (angalia Mchoro 3). Chagua kulingana na kasi na kiwango cha ishara zinazohitajika.
• Kuzuia mwanga wa mazingira:Ingawa ufungaji wa giza unasaidia, vyanzo vikali vya mwanga wa infrared vya mazingira (jua, balbu za incandescent) vinaweza kusatura sensor. Fikiria kutumia vichungi vya macho, kurekebisha chanzo cha mwanga wa infrared, na kutumia mbinu za kugundua kwa wakati mmoja.
• Kulipa fidia kwa joto:For precision analog sensing, it is necessary to compensate for changes in dark current and sensitivity with temperature within the signal conditioning circuit (Figure 1 and Figure 2).
• Electrical Noise:High-impedance nodes at the collector are susceptible to electromagnetic interference (EMI). Keep traces short, use shielding when necessary, and consider placing R_LConnect a small capacitor (e.g., 10-100pF) in parallel at both ends to filter out high-frequency noise, while noting its impact on speed.

8. Ulinganishi wa Teknolojia na Tofauti

Compared to a basic photodiode, a phototransistor like the LTR-1650D provides internal gain, producing a larger output current for the same light input, which often eliminates the need for an additional external amplifier in simple switching applications. Compared to a photodarlington transistor, it offers a faster response time (microseconds vs. tens/hundreds of microseconds) but lower gain. Its design for I_C(ON)Mfumo maalum wa kiwango, ikilinganishwa na vifaa vyenye maelezo makuu moja tu, huruhusu muundo sahihi zaidi wa mfumo. Ufungaji wa giza-uwazi ni tofauti muhimu na ufungaji wa uwazi, hutoa kazi ya kuzuia mwanga unaoonekana iliyojengwa ndani.

9. Maswali Yanayoulizwa Mara kwa Mara (Kulingana na Vigezo vya Kiufundi)

9.1 "BIN" maana yake ni nini, na ninawezaje kuchagua?

BIN codes (A through F) specify the guaranteed range of phototransistor sensitivity (I_C(ON)) . Select the grade based on the output current required for your specific irradiance level. For applications requiring higher sensitivity/lower light levels, choose a grade with a higher letter (e.g., E or F). For cost-sensitive applications where high gain is not critical, a lower grade (A or B) may be sufficient.

9.2 Why is dark current important?

Dark current (I_CEO) is the output signal present when no light is incident. It sets the lower limit of detectable light and acts as a noise source. In digital switching applications, the circuit's detection threshold must be set above the maximum expected dark current, especially at high temperatures where dark current increases significantly.

9.3 How does the load resistor affect performance?

Load resistance (R_L) directly affects two key parameters:Voltage ya pato(V_out= I_C* R_L) andSwitching speed(Tazama Mchoro 3). Lazima uchague R_Lili kutoa mabadiliko ya voltage muhimu kwa kiwango chako cha mantiki au ingizo la ADC, wakati huo huo kuhakikisha kuwa wakati wa kupanda/kushuka ni wa kutosha kwa kiwango cha data ya programu yako au wakati wa kukabiliana.

9.4 Je, naweza kuitumia kwenye mwanga mkali wa jua?

Kifuniko cha giza cha uwazi kinatoa uwezo fulani wa kuzuia, lakini mwanga wa moja kwa moja wa jua unajumuisha mnururisho mkali wa infrared, ambao kwa urahisi unaweza kusheheni sensor. Kwa matumizi ya nje, hatua za ziada lazima zichukuliwe: kivuli cha kimwili (kifuniko cha kivuli), kichujio cha mwanga cha ukanda nyembamba cha macho kilicholenga kwenye urefu wa wimbi la chanzo chako cha infrared (kwa mfano, 940nm), na kwa upendeleo kutumia chanzo cha infrared kilichorekebishwa na ugunduzi wa usawazishaji katika mzunguko wa mpokeaji, ili kutofautisha ishara na sehemu ya DC thabiti ya mwanga wa jua.

10. Utafiti wa Kesi za Uundaji na Matumizi Halisi

Tukio: Kubuni sensor ya kugundua karatasi kwa printer.

1. Model Selection:Select a medium sensitivity level (e.g., Class C or D) to ensure reliable triggering without being overly sensitive to dust or reflections.
2. Circuit Configuration:Tumia mpangilio wa kubadili wa emitter ya kawaida. LTR-1650D iwe pamoja na LED ya infrared (kwa mfano, 940nm) na kuwekwa upande mwingine wa njia ya karatasi.
3. Uamuzi wa Vigezo vya Vipengele:Chagua R_LThamani (mfano, 4.7kΩ), ili wakati kuna karatasi (kuzuia mwanga, I_CChini) pato la mantiki ya chini (karibu na 0V), wakati hakuna karatasi (kuna mwanga, I_CCJuu) pato la mantiki ya juu (karibu na V_C). Thibitisha viwango vya voltage vinavyolingana na pini za pembejeo za microcontroller.
4. Ukinzani wa kelele:Katika R_LUmewekewa capacitor ya 10nF sambamba kwenye ncha zote mbili, ili kuzuia kelele za umeme zinazotokana na motor ya printer. Kasi inayotokana (takriban 100µs) bado ni haraka zaidi kuliko mwendo wa mitambo wa karatasi.
5. Kulinganisha:Tumia mchoro wa mwelekeo wa unyeti (Mchoro 5) kuongoza muundo wa mitambo. Hakikisha LED ya infrared na transistor ya fotoelektrini zinalingana ndani ya pembe ya koni ya unyeti wa juu (mfano, ±20°) ili kuongeza kiwango cha juu cha nguvu ya ishara.
6. Jaribio:Jaribu sensoru katika hali mbaya zaidi: joto la juu (angalia ongezeko la mkondo wa giza) na kutumia aina mbalimbali za karatasi (baadhi zinaweza kuwa wazi zaidi kwa mwanga wa infrared).

11. Kanuni ya Uendeshaji

Kwa asili, fototransista ni transistor ya makutano ya bipolar (BJT) ambayo mkondo wa msingi wake hutokana na mwanga, sio usambazaji wa umeme. Foton za mwanga zinazoingia zenye nishati kubwa kuliko pengo la bendi ya semikondukta zinachukuliwa katika eneo la makutano ya msingi-kokotoa, na kuzalisha jozi za elektroni-na-shimo. Uga wa umeme katika makutano ya kokotoa-msingi yaliyopigwa kinyume husafirisha vibeba hivi, na kwa ufanisi kuzalisha mkondo wa mwanga unaofanya kazi kama mkondo wa msingi (I_B) Mkondo huu wa msingi unaozalishwa na mwanga kisha huongezewa kwa faida ya mkondo (h_FE) Amplification, producing a much larger collector current (I_C= h_FE* I_B). This internal amplification is its key advantage over simple photodiodes. The dark transparent packaging material acts as a long-pass filter, allowing infrared wavelengths (such as 940nm) to pass while absorbing shorter visible wavelengths, thereby improving the signal-to-noise ratio in environments with visible light.

12. Mienendo na Maendeleo ya Sekta

Ulimwengu wa optoelectronics unaendelea kukua. Ingawa transistor za pekee za mwanga kama LTR-1650D bado ni muhimu kwa matumizi yanayohitaji uwezo maalum, wingi mkubwa au unayohusisha gharama, mwelekeo mpana zaidi unajumuisha:

• Ujumuishaji:Kuunganisha kigunduzi cha mwanga na kivutio cha mbele cha analog, kigeuzi cha analog-hadi-digital (ADC) na mantiki ya dijiti katika suluhisho la chip moja (mfano, sensor ya mwanga wa mazingira, moduli ya sensor ya ukaribu). Suluhisho hizi hutoa pato la dijiti lililokalibriwa, eneo dogo la kuchukua na muundo uliorahisishwa, lakini gharama ya kila kitengo inaweza kuwa kubwa zaidi.
• Miniaturization:Demand for smaller package sizes (e.g., chip-scale packages) to accommodate shrinking consumer electronics.
• Performance Enhancement:Develop devices with lower dark current, faster response time (entering the nanosecond range), and higher sensitivity to meet more demanding applications such as LiDAR and high-speed communication.
• Specialization:Sensors customized for specific wavelengths (e.g., for heart rate monitoring, gas sensing) or with built-in spectral filters.

Discrete phototransistors are likely to maintain their position in applications where their simplicity, robustness, low cost, and specific performance characteristics (such as the dark package of the LTR-1650D) provide the optimal solution.