LTR-301 Phototransistor Datasheet - Side-View Package - Clear Lens - 30V Collector-Emitter Voltage - Simplified Chinese Technical Documentation

1. Product Overview

LTR-301 ni fototransista ya silikoni ya aina NPN, iliyobuniwa mahsusi kwa matumizi ya kugundua mionzi ya infrared. Inatumia ufungaji wa plastiki wenye lenzi wazi unaotazama kando, na imeboreshwa kwa kugundua mionzi ya infrared (kwa kawaida yenye urefu wa wimbi wa 940nm). Kifaa hiki kimekusudiwa kubadilisha nuru ya infrared inayoangukia kuwa mkondo wa umeme unaolingana kwenye terminali yake ya kolekta.

Kazi kuu ya kifaa hiki ni kufanya kazi kama kigeuzi cha nuru-hadi-mkondo. Mionzi ya infrared inapomgusa eneo la msingi lenye usikivu wa nuru la transista, husababisha kutokeza jozi za elektroni na mashimo. Mkondo huu unaotokana na nuru hutumika kama mkondo wa msingi, kisha unazidishwa na faida ya mkondo (β) ya transista, na kusababisha mkondo mkubwa zaidi wa kolekta. Ishara hii iliyozidishwa ni rahisi zaidi kuunganishwa na saketi za elektroni zinazofuata, kama vile mikadiliao au viendeshaji.

Faida zake za msingi zinajumuisha anuwai pana ya upeo wa uendeshaji wa mkondo wa kolekta, ambayo inatoa urahisi wa muundo wa kukidhi mahitaji tofauti ya usikivu. Lenzi iliyojumuishwa huongeza usikivu wake kwa kuzingatia nuru inayoangukia kwenye eneo lenye ufanisi. Mwelekeo wa ufungaji unaotazama kando unafaa mahsusi kwa matumizi ambapo chanzo cha nuru kiko sambamba na uso wa PCB, kama vile kizui-chembeu cha aina ya groove au sensorer ya kutafakari. Ufungaji wazi huruhusu mwitikio wa wigo mpana, ingawa umeboreshwa kwa nuru ya infrared.

Soko lengwa la kipengele hiki linajumuisha elektroniki za watumiaji, otomatiki ya viwanda, mifumo ya usalama, na matumizi mbalimbali ya kuhisi. Matumizi ya kawaida yanajumuisha kugundua vitu, kuhisi nafasi, vihesabu vya mzunguko, kugundua karatasi za kichapishi, na swichi zisizo za kugusa.

2. In-depth Technical Parameter Analysis

2.1 Absolute Maximum Ratings

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):100 mW. This is the maximum total power the device can dissipate as heat. Exceeding this limit risks thermal runaway and failure.
• Collector-Emitter Voltage (V_CEO):30 V. The maximum voltage that can be applied between the collector and emitter pins when the base is open (no illumination).
• Emitter-Collector Voltage (V_ECO):5 V. Upeo wa juu wa voltage ya nyuma inayoruhusiwa kati ya emitter na collector.
• Joto la uendeshaji (T_A):-40°C hadi +85°C. Masafa ya joto ya mazingira yanayohakikisha uendeshaji thabiti.
• Joto la uhifadhi (T_stg):-55°C hadi +100°C.
• Joto la kuunganishia pini:Umbali wa 1.6mm kutoka kwa mwili wa kifurushi, 260°C kwa sekunde 5. Hii ni muhimu kwa mchakato wa kuunganishia kwa wimbi au kwa mkono.

2.2 Electrical and Optical Characteristics

Vigezo hivi vinabainishwa kwa joto la mazingira (T_A) la 25°C, na vinafafanua utendaji wa kifaa chini ya hali maalum za majaribio.

• Voltage ya kuvunjika kwa Kolekta-Emita, V_(BR)CEO:30 V (kiwango cha chini). Imepimwa chini ya I_C= 1mA na bila mwanga (E_e= 0 mW/cm²). Hii inathibitisha viwango vya juu kabisa vilivyowekwa.
• Voltage ya kuvunjika kwa Emita-Kolekta, V_(BR)ECO:5 V (minimum). Tested at I_E= 100µA with no illumination.
• Collector-emitter saturation voltage, V_CE(SAT):0.4 V (maximum). This is the voltage drop across the transistor when it is fully "on" (saturated) under an irradiance of 1 mW/cm² and I_C= 0.1mA. For switching applications, a lower V_CE(SAT)helps minimize power loss.
• Rise time (T_r) and fall time (T_f):) are 10 µs (typical) and 15 µs (typical), respectively. These parameters define the switching speed. At V_CC=5V, I_C=1mA, R_L=1kΩ. Due to the charge storage effect, this asymmetry is common in phototransistors.
• Collector dark current (I_CEO):100 nA (max). This is the leakage current flowing from the collector to the emitter when the device is in complete darkness (E_e= 0 mW/cm²) and V_CE= 10V. Low dark current is crucial for achieving a good signal-to-noise ratio, especially in low-light sensing.

3. Grading System Description

LTR-301 inatumia mfumo wa kugawa daraja kwa kigezo chake muhimu cha sasa ya mkusanyiko katika hali ya uendeshaji (I_C(ON)). Kugawa daraja ni mchakato wa udhibiti wa ubora ambao vipengele vinagawanywa katika safu maalum au "daraja" kulingana na utendakazi uliopimwa. Hii inahakikisha uthabiti kwa mtumiaji wa mwisho.

Kigezo kinachogawiwa daraja ni I_C(ON), kinachopimwa chini ya hali zilizosanifishwa: V_CE= 5V, E_e= 1 mW/cm², λ = 940nm. Kulingana na pato la sasa lililopimwa, kifaa kinagawiwa katika mojawapo ya daraja nane (A hadi H).

• Daraja A:0.20 - 0.60 mA
• Gear B:0.40 - 1.08 mA
• Gear C:0.72 - 1.56 mA
• Gear D:1.04 - 1.80 mA
• Gear E:1.20 - 2.40 mA
• Gear F:1.60 - 3.00 mA
• Gear G:2.00 - 3.84 mA
• Gear H:2.56 mA (minimum)

Design Impact:Wakati wa kubuni sakiti, ni lazima uzizingatie vigezo vinavyotumika. Kwa mfano, kuchagua kifaa chenye kigezo H kunahakikisha unyeti wa chini zaidi kuliko kifaa chenye kigezo A. Hii ni muhimu sana wakati wa kuweka kizingiti cha kulinganisha au kiwango cha faida ya mfano. Ikiwa muundo wako unahitaji kiwango cha chini cha ishara, ni lazima ubainishe msimbo wa kigezo unaokidhi hitaji hilo.

4. Uchambuzi wa Mkunjo wa Utendaji

Waraka wa data hutoa mikunjo kadhaa ya sifa, inayoonyesha jinsi vigezo vinavyobadilika kulingana na hali ya uendeshaji.

4.1 Mkondo wa Giza wa Collector vs. Joto la Mazingira (Kielelezo 1)

Kielelezo kinaonyesha I_CEOinaongezeka kwa kasi ya kielelezo kadiri joto linavyoongezeka. Kwa 85°C, mkondo wa giza unaweza kuwa wa viwango kadhaa vya juu zaidi kuliko kwa 25°C. Hii ni sifa ya msingi ya semiconductor (mkondo wa uvujaji huongezeka mara mbili kila 10°C).Mambo ya Kuzingatia katika Ubunifu:Katika mazingira ya joto la juu, mkondo wa giza ulioongezeka unaweza kuchukuliwa vibaya kama ishara ya mwanga halisi. Mzunguko unaweza kuhitaji fidia ya joto au kizingiti cha juu zaidi cha kugundua.

4.2 Kupunguzwa kwa Nguvu ya Collector vs. Joto la Mazingira (Kielelezo 2)

Mkunjo huu unaonyesha nguvu ya juu inayoruhusiwa (P_C) hupungua kwa mstari kadiri joto la mazingira (T_A) linapoinuka zaidi ya 25°C. Kwenye 85°C, nguvu ya juu inapungua kwa kiasi kikubwa.Mambo ya Kuzingatia katika Ubunifu:Hakikisha nguvu ya uendeshaji (V_CE* I_C) inabaki chini ya mstari wa kupunguzwa kwa nguvu kwenye T_Aya juu inayotarajiwa, ili kuzuia mzigo mwingi wa joto.

4.3 Muda wa Kupanda/Kushuka vs. Upinzani wa Mzigo (Kielelezo 3)

Grafu hii inaonyesha usawazishaji kati ya kasi ya kubadili na ukubwa wa ishara. Kadiri upinzani wa mzigo (R_L) unavyoongezeka, muda wa kupanda na kushuka pia huongezeka. R kubwa zaidi_Linaweza kutoa mabadiliko makubwa ya voltage ya pato (ΔV = I_C* R_L), lakini hupunguza kasi ya kukabiliana.Mambo ya Kuzingatia katika Ubunifu:Kwa matumizi ya kasi ya juu (k.m. mawasiliano ya data), tumia R ndogo_L. Kwa kuongeza kiwango cha juu cha voltage ya pato katika matumizi ya polepole (k.m. kugundua mwanga wa mazingira), R kubwa zaidi inaweza kutumika._L。

4.4 Relative Collector Current vs. Irradiance (Figure 4)

Hii ni mkunjo wa sifa ya uhamishaji, unaonyesha kwamba wakati V_Cimewekwa (5V), katika safu fulani, mkondo wa mkusanyiko (I_e) unalingana na nguvu ya mwanga inayoangukia (mnururisho, E_CE) Inasemavyo takriban mstari. Uwiano huu wa mstari ni muhimu kwa matumizi ya kupima mwanga wa analog.

4.5 Sensitivity Pattern (Figure 5)

Mchoro huu wa polar unaonyesha usikivu wa kona wa kifaa. Phototransistor ina usikivu mkubwa zaidi kwa mwanga unaoingia perpendicular kwa lenzi (0°). Usikivu hupungua kadri pembe ya matukio inavyoongezeka, kwa kawaida hufikia 50% (nusu pembe) kwa pembe maalum (kama zinavyopendekezwa ±10° hadi ±20° kwenye mchoro).Mambo ya Kuzingatia katika Ubunifu:Hii inafafanua pembe ya uwanja wa maono. Ulinganifu sahihi wa mitambo kati ya kitoa na kigundua ni muhimu sana. Pia inaweza kutumika kukandamiza mwanga usiotakiwa kutoka kwa mwelekeo usiofaa.

5. Mechanical and Packaging Information

Kifaa hiki kinatumia ufungaji wa plastiki uwazi, unaoangalia kando. Neno "kuangalia kando" linaonyesha kuwa eneo lenye usikivu wa mwanga liko kwenye upande wa kifaa, sambamba na pini, na sio juu. Hii inafaa kabisa kwa kuhisi ndani ya ndege ya PCB.

Maelezo muhimu ya vipimo:

• All dimensions are in millimeters, with a general tolerance of ±0.25mm unless otherwise specified.
• Pin pitch is measured at the point where the leads exit the package body, which is critical for PCB footprint design.
• The package incorporates a lens molded into the plastic to enhance optical collection efficiency.

Polarity Identification:The longer lead is typically the collector. However, always refer to the package outline in the full datasheet for final identification, usually indicated by a flat on the package or a mark on the lens.

6. Soldering and Assembly Guide

The key parameter provided is the lead soldering temperature: maximum 260°C for 5 seconds, measured at a point 1.6mm (0.063 inches) from the package body. This is the standard rating for through-hole components.

Process Recommendation:

• Wave Soldering:Ensure the temperature profile at the pin/package junction does not exceed the specified limits. Preheating is critical to minimize thermal shock.
• Hand Soldering:Use a temperature-controlled soldering iron. Heat the pin/pad junction quickly and efficiently, avoiding prolonged contact with the component body.
• Cleaning:Tumia kioevu cha kusafisha kinacholingana na nyenzo za kufunga plastiki. Epuka kutumia usafishaji wa mawimbi ya sauti isipokuwa umehakikisha kuwa salama kwa kifaa.
• Uhifadhi:Hifadhi katika mazingira yaliyokauka, yanayozuia umeme wa tuli, ndani ya anuwai ya halijoto maalum (-55°C hadi +100°C) ili kuzuia unyevunyevu (unaoweza kusababisha "popcorn effect" wakati wa upakiaji tena) na uharibifu kutokana na utokaji umeme wa tuli.

7. Vidokezo vya Matumizi na Mazingatio ya Ubunifu

7.1 Saketi ya Kawaida ya Matumizi

1. Kigeuzi cha Dijiti (Kugundua Kitu):Transista ya Mwanga imeunganishwa mfululizo na upinzani wa kuvuta juu (R_L) kwenye V_CC. The collector node is connected to a digital input (e.g., a microcontroller GPIO or a Schmitt trigger). In darkness, I_Cis very low (I_CEO), so the output is pulled high to V_CC. When illuminated, I_Cincreases, pulling the output voltage low to near V_CE(SAT). The value of R_Lis chosen based on the required switching speed (see Figure 3) and the desired logic low voltage level: R_L≈ (V_CC- V_CE(SAT)) / I_C(ON).

2. Analog Light Meter:The phototransistor is connected in a similar configuration, but the collector voltage is fed to an analog-to-digital converter (ADC) input. Due to the roughly linear relationship shown in Figure 4, the ADC reading can be correlated with light intensity. A higher R_Lprovides a larger voltage swing for better ADC resolution but reduces bandwidth.

7.2 Sababu Muhimu za Ubunifu

• Light Source Matching:For optimal performance, pair the phototransistor with an infrared LED emitter that has the same peak wavelength (940nm).
• Electrical Load:The phototransistor is a current source. The load resistor converts this current into a voltage. Select R_LTo balance signal level, speed, and power consumption.
• Ambient Light Rejection:This device responds to all light, not just infrared. Use an optical filter (black IR-transmissive plastic) or a modulated (pulsed) light source with synchronous detection to suppress ambient 50/60Hz light noise and DC ambient light.
• Biasing:Ensure the operating V_CEis within the recommended range (well below 30V) and that the power dissipation (V_CE* I_C) is within limits, especially at high temperatures.

8. Ulinganishi wa Kiufundi na Tofauti

Ikilinganishwa na photodiode, phototransistor hutoa faida ya ndani, ikizalisha ishara kubwa ya pato chini ya mwangaza sawa wa pembejeo, na kurahisisha muundo wa kifaa cha kuongeza nguvu kinachofuata. Hata hivyo, hii inafanyika kwa gharama ya muda wa kukabiliana polepole zaidi (phototransistor kwa kiwango cha µs, photodiode kwa kiwango cha ns) na unyeti wa juu wa joto wa mkondo wa giza.

Tofauti maalum ya LTR-301 iko katikaUfungaji wa kuona kwa upande(sio ya kawaida kama aina ya kuona juu) naLensi ya uwazi(ikilinganishwa na yenye rangi au nyeusi). Lensi ya uwazi hutoa mwitikio mpana wa wigo, ambao unaweza kuwa faida au hasara, kulingana na ikiwa inahitajika kuzuia mwanga unaoonekana. Mfumo wa kina wa kugawanya katika makundi huruhusu uteuzi sahihi wa usikivu, ambao ni faida muhimu kwa uzalishaji mkubwa unaohitaji utendakazi thabiti.

9. Maswali Yanayoulizwa Mara kwa Mara (FAQ)

Swali: Kuna tofauti gani kati ya viwango tofauti? Ni ipi ninapaswa kuchagua?
Jibu: Viwango vinatofautishwa kulingana na unyeti wa kifaa (I_C(ON)). Chagua kiwango kulingana na mkondo wa chini wa ishara unaohitajika na mzunguko. Kwa unyeti wa juu zaidi/umbali mrefu zaidi, chagua kiwango cha juu zaidi (k.m. H). Kwa matumizi yanayohitaji gharama nafuu na unyeti wa chini unakubalika, kiwango cha chini (k.m. A) kinaweza kutosha.

Swali: Kwa nini ishara yangu ya pato ina kelele au haina utulivu?
Jibu: Hii kwa kawaida husababishwa na mwanga wa mazingira (jua, taa ya fluorescent) au kelele ya umeme. Suluhisho ni pamoja na: 1) Kutumia chanzo cha mwanga wa infrared kilichorekebishwa na kuchuja ishara iliyopokelewa. 2) Kuunganisha capacitor (10nF - 100nF) sambamba na upinzani wa mzigo R_Lili kuchuja kelele ya masafa ya juu (hii itapunguza kasi ya majibu). 3) Kuhakikisha ulinzi na kutuliza kwa usahihi.

Swali: Naweza kuitumia pamoja na chanzo cha mwanga unaoonekana?
Jibu: Ndio, ufungaji wazi unamaanisha kuwa itajibu pia kwa mwanga unaoonekana pamoja na mwanga wa infrared. Hata hivyo, unyeti wake kwa kawaida unapimwa na kuboreshwa kwa mwanga wa infrared wa 940nm. Majibu kwa mwanga unaoonekana yatakuwa tofauti, na hayajadaiwa katika karatasi ya data.

Swali: Ninawezaje kuhesabu uwiano wa majibu au unyeti?
A: Responsivity is not directly given. You can estimate it from the I_C(ON)specifications. For example, for Grade E (minimum 1.20mA at 1 mW/cm²), the minimum responsivity is approximately 1.20 mA / (1 mW/cm²) = 1.20 mA/(mW/cm²). Note that this is a rough estimate as the effective area is not specified.

10. Mifano ya Matumizi Halisi

Scenario: Paper detection in a printer.Build a reflective sensor using an LTR-301 and an infrared LED. Place them side-by-side, facing the paper path. The IR LED is constantly on. When no paper is present, light reflects weakly from a distant surface, resulting in low phototransistor output. When paper passes directly under the sensor, it reflects a strong signal back to the phototransistor, causing I_Cto increase sharply, and the collector node voltage drops accordingly.

Design Steps:
1. Select a grade (e.g., Grade D or E) that provides sufficient signal current from the expected paper reflection.
2. Select R_LFor a 5V power supply, the target logic low voltage is 0.8V, and using the current I from gear D_C(ON,min)(1.04mA): R_L≤ (5V - 0.8V) / 1.04mA ≈ 4.0kΩ. A standard 3.3kΩ resistor will be suitable, providing good signal margin.
3. Connect the collector node to a comparator or microcontroller interrupt pin. Set a threshold voltage (e.g., 2.5V) at the inverting input of the comparator to reliably detect paper presence/absence.
4. Mechanically align the sensor so that the infrared LED's beam and the phototransistor's field of view intersect at the paper surface.

11. Kanuni ya Uendeshaji

A phototransistor is essentially a Bipolar Junction Transistor (BJT) whose base current is generated by light, not an electrical connection. In an NPN phototransistor like the LTR-301:

1. Infrared photons with sufficient energy (for silicon, wavelength ≤1100nm) penetrate the transparent package and are absorbed by the semiconductor material (primarily in the base-collector depletion region).
2. Kunyonya huku hutoa jozi za elektroni-nafasi.
3. Uga wa umeme katika makutano ya msingi-mkusanyiko uliyopinduliwa hutenganisha vibeba hivi: elektroni kwenda kwenye mkusanyiko, nafasi kwenda kwenye msingi.
4. Mkusanyiko wa nafasi katika eneo la msingi hupunguza kizuizi cha msingi-toa, kikifanya kazi kama mkondo chanya wa msingi (I_B).
5. Kisha, mkondo huu wa msingi unaozalishwa na mwanga hukuza kwa faida ya mkondo wa transistor (β au h_FE), na kutoa mkondo wa mkusanyiko: I_C= β * I_B(photo)Hii ndiyo chanzo cha faida ya kifaa.

Ufungaji wa mtazamo wa upande huweka makutano haya yanayokamata mwanga kando, na huwa na lenzi iliyokusudiwa kuzingatia mwanga unaoingia ili kuboresha ufanisi.

12. Mwelekeo wa Teknolojia

Transista za fotoelektriki kama LTR-301 zinawakilisha teknolojia iliyokomaa na yenye thamani nafuu. Mielekeo ya sasa ya kugundua mwanga inajumuisha:

• Ujumuishaji:Mwelekeo kuelekea suluhisho zilizojumuishwa, ambazo zinachanganya kigunduzi cha mwanga, kikuza sauti, kifaa cha kidijitali, na saketi za mantiki (k.m. sensorer ya mwanga yenye pato la I²C) kwenye chipi moja, na hivyo kupunguza idadi ya vipengele vya nje na kurahisisha muundo.
• Miniaturization:Developing smaller surface-mount device (SMD) packages for phototransistors for space-constrained applications.
• Specialization:Devices with built-in spectral filters (e.g., for RGB sensing or specific IR bands) or daylight-blocking filters are becoming increasingly common for robust operation in various environments.
• High-Speed:Although phototransistors are generally slower than photodiodes, ongoing development aims to increase their bandwidth for data communication applications (e.g., infrared remote controls, simple optical data links).

Despite these trends, discrete phototransistors remain highly relevant due to their simplicity, low cost, high sensitivity, and the design flexibility offered by configuring gain and bandwidth with external components.