ELQ3H4 Optocoupler Datasheet - 16-Pin SSOP Package - AC Input - Current Transfer Ratio 20-300% - Isolation Voltage 3750Vrms - Technical Documentation

1. Product Overview

The ELQ3H4 series is a class of optocoupler isolators designed for high-density applications requiring reliable signal isolation. Its core component consists of a gallium arsenide light-emitting diode optically coupled to a silicon NPN phototransistor, all housed within a compact 16-pin ultra-thin small outline package. A key feature of this package is the integrated light shield, which effectively reduces the impact of ambient light on the phototransistor's performance, thereby enhancing signal integrity in noisy electrical environments.

The device is designed to directly accept AC input signals, eliminating the need for external rectification circuits in many applications. Its primary value proposition lies in combining an extremely small form factor with robust isolation performance, while complying with major international safety and environmental standards._RMS。

1.1 Core Advantages and Target Market

ELQ3H4 optocoupler inatoa faida kadhaa muhimu. YakeHalogen-freeThe construction and compliance with RoHS and lead-free directives make it suitable for environmentally conscious designs. The device is certified by leading safety agencies including UL, VDE, SEMKO, NEMKO, DEMKO, FIMKO, and CQC, facilitating its use in products for global markets with stringent regulatory requirements.

Its primary target application areas are industrial automation and measurement, where noise immunity and safety are critical. These applications include:

• Programmable Logic Controllers:Used to isolate digital I/O signals, communication buses, or analog sensor inputs from the central processing unit.
• Measuring Instrument:Provides isolation in data acquisition systems, multimeters, or oscilloscopes to protect sensitive circuits from high-voltage test points.
• Hybrid Integrated Circuits and Power Supplies:Used as a feedback component in isolated switching power supplies, or in custom hybrid modules for gate driving or signal conditioning.

2. In-depth Technical Parameter Analysis

Kuelewa kwa kina vigezo vya umeme na vya nuru ni muhimu kwa muundo thabiti wa saketi. Sehemu ifuatayo inachambua kwa undani vipimo muhimu.

2.1 Absolute Maximum Ratings

Viwango hivi hufafanua mipaka ya mkazo inayoweza kusababisha uharibifu wa kudumu wa kifaa. Uendeshaji chini ya hali hizi haupendekezwi. Mipaka muhimu ya ELQ3H4 ni pamoja na:

• Input side:Continuous forward current is ±60mA, and the 1μs pulse current is 1A. The power dissipation per channel is 70mW, with a derating factor of 0.7mW/°C._FF_FPFP
• Output side:The collector current is 50mA. The collector-emitter voltage is 80V, while the emitter-collector voltage is lower at 7V, indicating the asymmetry in the breakdown characteristics of the phototransistor. The power dissipation per channel output is 150mW, with a derating factor of 1.4mW/°C._CC_CEOCEO_ECOECO
• Kutengwa na Mazingira:Kifaa hiki kinaweza kustahimili kwa dakika moja ya_ISO3750 V_RMSVoltage ya kutengwa. Anuwai ya joto la kufanya kazi ni kutoka -55°C hadi +110°C.

2.2 Electrical and Optical Characteristics

Vigezo hivi vinafafanua utendaji wa kifaa chini ya hali za kawaida za uendeshaji._AA

Tabia za Ingizo:Voltage ya mbele ya LED ya Gallium Arsenide kwa I_FF_F= 20mA ni 1.2V kwa kawaida, na kiwango cha juu ni 1.4V. Uwezo wa ingizo unaweza kufikia hadi 250pF, ambayo inaweza kuathiri utendaji wa kubadili wa masafa ya juu._F) is up to 250pF, which can affect high-frequency switching performance.

Sifa za Pato:When the light-emitting diode is off, V_CEOCEO_CEAt =20V, the maximum collector-emitter dark current is 100nA, representing the leakage current of the phototransistor. The breakdown voltage confirms its asymmetric structure._CEOCEO_ECOECO

Transfer Characteristics:_AThis is the core of optocoupler performance.Current Transfer Ratio:

• Inafasiriwa kama chini ya hali maalum (IC_CF_F/ I_F) * 100%. ELQ3H4 katika I_CEF
• = 1mA, VCEO
• = 5V ina CTR safu pana sana, kuanzia 20% hadi 300%. Safu hii pana inamaanisha muundo wa sakiti unaoangaliwa kwa makini au kugawanywa katika viwango katika matumizi sahihi. V_{CTR uwiano:}This parameter ranges from 0.5 to 2.0, indicating the matching degree between channels in multi-channel devices or the consistency of CTR under AC operation. A ratio of 1.0 indicates perfect matching._FSaturation Voltage:_CAt I
• C=20mA, I_IOF¹⁰When =1mA, the typical value is 0.1V, indicating good switching characteristics when driven to saturation._IOIsolation parameters:
• Minimum isolation resistance is 5 x 1010_rΩ, typical isolation capacitance is 0.3pF. Low capacitance is crucial for suppressing high-frequency common-mode noise._fSwitching speed:_CEKatika V_CCC_L=2V, I

F

=2mA, R

• L_FUnder the test condition of =100Ω, both the rise time and fall time are specified as a maximum of 18μs. This indicates that the device is suitable for medium-to-low frequency digital signal transmission, not for high-speed data transfer.3. Performance Curve Analysis_FThe datasheet references typical optoelectronic characteristic curves. Although the specific graphs are not reproduced in the provided text, they typically illustrate the following relationships crucial for design:
• CTR vs. Forward Current:Inaonyesha jinsi ufanisi wa usafirishaji unavyobadilika kulingana na mabadiliko ya mkondo wa kuendesha diode inayotoa mwanga. CTR kwa I
• F_Fya juu sana kwa kawaida hupungua kwa sababu ya kupungua kwa ufanisi wa diode inayotoa mwanga.Uhusiano wa CTR na joto:
• Inaelezea utegemezi wa joto wa ufanisi wa kuunganisha, ambao kwa kawaida hupungua kadiri joto linavyoongezeka._CUhusiano wa voltage ya mbele na joto:_CEInaonyesha mgawo hasi wa joto wa voltage ya mbele ya diode inayong'aa.Uhusiano wa mkondo wa kolekta na voltage ya kolekta-to-emitter:
• Tabia ya pato ya transistor inayohisi mwanga chini ya mikondo tofauti ya pembejeo, sawa na mkunjo wa transistor ya aina ya bipolar._LUhusiano wa wakati wa kubadili na upinzani wa mzigo:Inaonyesha jinsi wakati wa kupanda na kushuka unavyoathiriwa na mzigo wa pato. R kubwa_LL

Kwa kawaida huongeza wakati wa kupanda kwa sababu ya kuongezeka kwa RC time constant.

Wabunifu wanapaswa kukagua data kamili ya michoro ili kuboresha sehemu ya kufanya kazi kulingana na mahitaji yao maalum ya kasi, matumizi ya nguvu na uthabiti wa joto.

4. Mechanical and Packaging Information

4.1 Package Dimensions and Layout

A The ELQ3H4 employs a 16-pin SSOP package with a profile height of only 2.0mm, enabling high-density PCB mounting. The datasheet includes detailed dimension drawings specifying the package's length, width, height, lead pitch, and lead size. Adherence to these mechanical specifications is crucial for proper mounting on the PCB and compatibility with automated assembly equipment.Imetolewa kwa ajili ya usanikishaji wa kufungia kwenye uso.

Recommended Pad Layout

Kufuata muundo huu wa pedi ni muhimu kuhakikisha umbo thabiti la mnyororo wa kuuza, nguvu ya mitambo inayofaa, na kuepuka matatizo kama vile kusimama wima wakati wa kuyeyusha tena. Muundo huu umezingatia umbo la pembe za kuuza na utoaji wa joto.4.2 Device Marking and Polarity.

• The device marking is on the top of the package. The marking format is as follows:EL Q3H4 YWW V
• EL:Manufacturer Identifier.
• Q3H4:Device model.
• Y:Single-digit year code.
• WW:Two-digit year week code.

V:

Indicates the optional marking for VDE certification.

Mwelekeo sahihi ni muhimu sana. Kiashiria cha pini 1 kwenye kifurushi lazima iendane na alama ya pini 1 kwenye kifurushi cha PCB. Kuingizwa vibaya kutasababisha kifaa kushindwa kufanya kazi na kunaweza kusababisha uharibifu.

5. Mwongozo wa Kuunganisha na Usanikishaji5.1 Masharti ya Kuunganisha kwa reflowThis device is suitable for surface mount reflow soldering. The datasheet specifies the critical

• Maximum Body Temperature Profile. Key parameters include:
• Preheating:_LIncrease from 150°C to 200°C within 60-120 seconds.Time Above Liquidus:
• 60-100 seconds._PPeak Temperature:Maximum 260°C.
• Time within ±5°C of peak temperature:Maximum 30 seconds.
• Maximum number of reflows:Mara 3.

Kufuata mduara huu wa joto kwa uangalifu huzuia uharibifu wa joto kwa kifuniko cha plastiki, muunganisho wa waya wa ndani, na chipu ya semiconductor. Kuzidi kiwango cha juu cha joto au muda wa joto la juu kunaweza kusababisha kutenganishwa, kuvunjika, au kupotoka kwa vigezo.

5.2 Operation and Storage

Standard ESD precautions must be observed because the internal GaAs LED and silicon phototransistor are susceptible to electrostatic damage. Use a grounded workbench and wrist strap. Devices should be stored in their original moisture barrier bag and placed in a controlled environment to prevent moisture absorption, which can cause the "popcorn" effect during reflow soldering.

6. Packaging and Ordering Information

6.1 Model and Options

Muundo wa Nambari ya Sehemu ni kama ifuatavyo:ELQ3H4(Z)-V.

• Z:"TA" inamaanisha ufungaji wa mkanda. Ikiwa itaachwa, chaguo-msingi ni ufungaji wa mabomba.
• V:Inaonyesha alama ya uthibitisho wa VDE.

Idadi ya ufungaji:Chaguo la mfereji: vifaa 40 kwa kila mfereji. Chaguo la mkanda uliochongwa: vifaa 1000 kwa kila mkanda.

6.2 Reel Specifications

Detailed carrier tape dimensions are provided, including pocket size, pitch, and reel dimensions. This information is necessary for proper configuration of automatic placement equipment. The carrier tape width is 16.0mm ± 0.3mm, and the feed direction is specified.

7. Application Design Considerations

7.1 Input Circuit Design

ForAC InputOperation, light-emitting diodes can be directly driven by an AC signal. A current-limiting resistor must be used to set the desired forward current. Its resistance value must be calculated based on the peak voltage of the AC signal, the forward voltage of the LED, and the desired forward current. Since an LED is a diode, it will conduct only during a half-cycle unless a bridge rectifier is used at its front end for full-wave operation. A wide CTR range means that if a fixed forward current is used, the output current will vary significantly between different devices. For more consistent performance, consider using a higher forward current or implementing feedback._FF_FF_FF_FF_FF

3.2 Output Circuit Design

Phototransistors can be used forSwitch或LinearMode. For digital switching, the device is driven into saturation. The load resistor connected to the collector determines the output voltage swing and affects the switching speed. For analog or linear applications, the phototransistor operates in its active region. However, the nonlinearity of the CTR versus forward current curve and its strong temperature dependence make precise linear operation challenging without compensation._FF_CECE_CE(sat)L_LL_LF_F7.3 Immunity and Layout

To maximize high isolation capability, careful PCB layout is crucial. Maintain sufficient creepage distance and electrical clearance between the input and output sides of the circuit according to safety standards. Use a ground plane, but consider splitting the ground plane beneath the optocoupler to minimize capacitive coupling across the isolation barrier. Placing bypass capacitors close to both sides of the device pins helps suppress high-frequency noise.

rms_rmsIO_IO8. Technical Comparison and Selection Guide

The key differentiating feature of the ELQ3H4 is its

AC Input Capability、, Ultra-Small SSOP PackageandComprehensive Safety CertificationsWakati wa kuchagua optocoupler, linganisha mambo yafuatayo kulingana na mahitaji ya mradi:

• Ikilinganishwa na optocoupler ya pembejeo ya DC:ELQ3H4 hurahisisha mzunguko kwa kuondoa rectifier ya nje ya ishara ya AC, na kuokoa nafasi ya bodi na gharama.
• Ikilinganisha na ufungaji mkubwa zaidi:Ufungaji wa SSOP unatoa akiba ya nafasi inayoonekana, lakini unaweza kuwa na sifa tofauti kidogo za joto na unahitaji usanikishaji sahihi zaidi.
• Ikilinganisha na kuunganisha mwanga wa kasi:Vifaa vyenye milango ya kimantiki ya kasi zaidi au vijitenga vya dijiti vinatoa viwango vya juu vya data, lakini vinaweza kuwa na viwango tofauti vya ujitenga, mahitaji ya nguvu au muundo wa gharama.
• Ikilinganishwa na mwongozo wa pato la Darlington:Usanidi wa Darlington hutoa CTR ya juu zaidi, lakini kasi ya kubadili ni ya polepole zaidi na voltage ya kujaa ni ya juu zaidi.
• Uchaguzi wa kiwango cha CTR:If the circuit performance is highly sensitive to gain, inquire whether devices graded to a narrower CTR range are available.

9. Frequently Asked Questions

Q1: Can I drive the LED directly with a voltage source?
A1: Hapana. Diode inayotoa mwanga ni kifaa kinachodhibitiwa na mkondo. Lazima kila wakati utumie upinzani wa kuzuia mkondo uliosanidiwa mfululizo kudhibiti mkondo wa mwelekeo sahihi na kuzuia uharibifu wa mkondo kupita kiasi._FF

Q2: Kwa nini wakati wa kupanda wa pato katika hati ya maelezo ni polepole kuliko wakati wa kushuka?
A2: Hii ni ya kawaida kwa phototransistor. Wakati wa kupanda umepunguzwa na muda unaohitajika kuchaji capacitance ya kiunganishi cha phototransistor kupitia mkondo wa mwanga. Wakati wa kushuka umedhamiriwa na utokaji wa capacitance hiyo kupitia upinzani wa mzigo wa nje na mchakato wa recombination ndani ya kifaa.

Q3: Jinsi joto linavyoathiri utendaji?
A3: CTR kwa kawaida hupungua kadri joto linavyopanda. Voltage ya mbele ya LED pia hupungua. Athari hizi lazima zizingatiwe katika miundo inayofanya kazi katika anuwai ya joto pana, ili kuhakikisha kizingiti cha kuegemea cha kubadili au mstari._FF

Q4: Madhumuni ya "athari ya kuzuia mwanga" iliyotajwa ni nini?
A4: Ufungaji wa plastiki usio na uwazi hufanya kazi kama kifuniko cha kuzuia mwanga, kuzuia mwanga wa mazingira kufikia transistor nyeti-kwa-mwanga. Hii inazuia kusababishwa kwa makosa au mkondo wa upendeleo unaosababishwa na vyanzo vya mwanga vya nje.

10. Mfano wa Utumizi Halisi

Mandhari: Inatumika kwa Uchunguzi wa Mains AC Uliotengwa kwa Moduli ya Ingizo ya PLC.
A common use case is detecting the presence of a 120V AC signal from a switch or sensor. The ELQ3H4 is ideally suited for this application.

1. Input circuit:The 120V AC signal is stepped down through a high-impedance, high-voltage resistor network to limit current. A reverse protection diode can be connected in parallel across the LED to clamp the reverse voltage during the negative half-cycle, although the device is rated for AC operation. The resistor value is chosen to set the forward current to a nominal 5-10mA, well within the rated limits._FF
2. Output circuit:Kolekta ya fototransistor imeunganishwa kwa voltage ya umeme ya mantiki ya PLC kupitia upinzani wa kuvuta juu. Emeta imewekwa chini. Wakati kuna mkondo wa AC, fototransistor inaendesha katika nusu-mzunguko ulio na uendeshaji, ikivuta pato la kolekta chini. Ingizo la dijiti la PLC husoma ishara hii ya chini ya mapigo. Kisha, programu inaweza kufanya udhibiti wa kutetemeka au kugundua sehemu ya sifuri ili kuthibitisha uwepo wa mkondo wa AC._LL
3. Faida:Ubunifu huu unatoa utengano thabiti wa umeme, kulinda nyeti za mzunguko wa PLC kutokana na mabadiliko ya ghafla ya umeme na hitilafu. Ufungaji wa kompakt SSOP huruhusu kuwekewa kwa njia nyingi kama hizi kwenye moduli moja.

11. Kanuni ya Uendeshaji

Munganishaji wa Mwanga unategemeaMuunganisho wa MwangaKanuni hufanya kazi ili kufikia utengano wa umeme. Ishara ya umeme ya pembejeo inaendesha diode inayotoa mwanga, ikitoa mwanga wa infrared unaolingana na sasa. Mwanga huu hupita pengo fupi la uwazi ndani ya kifurushi, na kufikia eneo la msingi la transistor ya silikoni inayohisi mwanga. Fotoni zinazoingia husababisha jozi za elektroni-na-shimo katika eneo la msingi, kwa ufanisi kuchukua nafasi ya sasa ya msingi. Sasa hii inayotokana na mwanga kisha huongezwa kwa faida ya transistor, ikitoa sasa ya kolekta ambayo ni nakala ya umeme ya ishara ya pembejeo. Ufunguo ni kwamba usafirishaji wa ishara unafanywa kupitia mwanga, hakuna muunganisho wa umeme kati ya pembejeo na pato, na hivyo kuunda kizuizi cha utengano.

12. Mwelekeo wa Teknolojia

Uwanja wa utengano wa ishara unaendelea kukua. Ingawa viunganishi vya jadi kama ELQ3H4 vinavyotegemea transistor inayohisi mwanga bado vinatawala katika matumizi ya gharama nafuu, kasi ya wastani na utengano wa juu, kuna mwelekeo kadhaa muhimu:

• Kuongezeka kwa Kiunganishi:Viunganishi vya mwanga vya njia nyingi ndani ya kifuniko kimoja ni ya kawaida, hupunguza nafasi ya bodi na gharama kwa kila njia.
• Njia Mbadala za Kasi za Juu:Kwa mawasiliano ya data, vihifadhi vya dijiti vinavyotegemea teknolojia ya CMOS na mawasiliano ya redio au uwezo wa umeme hutoa viwango vya juu zaidi vya uhamishaji data, matumizi ya nguvu ya chini, na uthabiti bora wa muda, ingawa kwa kawaida huwa na viwango tofauti vya voltage ya kutengwa.
• Uthabiti ulioboreshwa na uthibitisho:Kusukuma endelevu kwa viashiria vya juu zaidi vya uthabiti, anuwai pana ya halijoto ya uendeshaji, na kupata uthibitisho wa viwango vipya, hasa katika matumizi ya magari na matibabu.
• Ufinyuaji wa kifurushi:Msukumo endelevu kuelekea ufumbaji mdogo na nyembamba zaidi umefanya bidhaa za mwisho kuwa za mkusanyiko mkubwa zaidi, kama inavyoonyeshwa na SSOP yenye urefu wa 2.0mm inayotumika katika ELQ3H4.