EL2514-G Optocoupler Datasheet - 4-Pin DIP Package - Isolation Voltage 5000Vrms - Current Transfer Ratio 50-200% - Technical Documentation

1. Product Overview

EL2514-G serisi, yüksek performanslı 4 pinli Çift Sıralı Diziliş Paketli (DIP) fototransistör tipi optokuplörlerdir. Bu cihazlar, iki devre arasında güvenilir elektriksel izolasyon ve sinyal iletimi sağlamak üzere tasarlanmıştır. Temel bileşeni, bir silikon fototransistör dedektörüne optik olarak bağlanmış bir kızılötesi ışık yayan diyottur. EL2514-G'in önemli bir tasarım özelliği, yük direnci kiloohm seviyelerinde olsa bile göreceli olarak yüksek anahtarlama hızları için optimize edilmiş olmasıdır. Bu, onu hem izolasyon hem de orta bant genişliği gerektiren uygulamalar için uygun kılar.

The series is characterized by compliance with stringent environmental and safety standards. It is manufactured using a halogen-free process, with bromine (Br) and chlorine (Cl) content meeting specific limits. Furthermore, it has obtained certifications from major international safety agencies including UL, cUL, VDE, SEMKO, NEMKO, DEMKO, FIMKO, and CQC, ensuring its suitability for global markets and regulated applications.

2. Detailed Technical Parameters

2.1 Absolute Maximum Ratings

This device is designed to operate reliably within specified limits. Exceeding these absolute maximum ratings may cause permanent damage. Key ratings include: continuous forward current (I_F) for the input LED is 50 mA, and the peak forward current (I_FP) is 0.5 A, and the reverse voltage (V_R) is 6 V. On the output side, the collector current (I_C) is rated at 20 mA, and the collector-emitter voltage (V_CEO) is 40 V. The total power consumption (P_TOT) is 200 mW. A key safety parameter is the isolation voltage (V_ISO) is 5000 V_rms, under specific humidity conditions (40-60% RH), with input and output pins short-circuited respectively, test for 1 minute. The operating temperature range is wide, from -55°C to +110°C.

2.2 Electro-Optical Characteristics

These parameters define the performance of the device under normal operating conditions at 25°C.

2.2.1 Input Characteristics (LED Side)

• Forward Voltage (V_F):The typical value is 1.2 V, with a maximum of 1.4 V when driven at I_F= 20 mA. This is crucial for designing the power supply voltage of the drive circuit.
• Reverse current (I_R):at V_R= 4V is a maximum of 10 µA, indicating good diode characteristics.
• Input capacitance (C_in):The capacitance ranges from a typical 30 pF to a maximum of 250 pF. This capacitance affects the high-frequency drive capability.

2.2.2 Output Characteristics (Phototransistor Side)

• Collector-Emitter Dark Current (I_CEO):When the LED is off and V_CE= 10V, the maximum is 100 nA. This low leakage current is crucial for achieving a good "off" state.
• Collector-Emitter Breakdown Voltage (BV_CEO):Minimum 40 V, measured under I_C= 0.1 mA condition.
• Emitter-Collector Breakdown Voltage (BV_ECO):The minimum is 0.45 V, which is relatively low, indicating the asymmetry of the phototransistor.

2.2.3 Transfer Characteristics

• Current Transfer Ratio (CTR):This is a core performance metric, defined as (I_C/ I_F) * 100%. For the EL2514-G, under standard test conditions I_F= 5 mA and V_CEAt 5V, the CTR range is 50% to 200%. This wide range requires appropriate circuit design to accommodate variations between devices.
• Collector-Emitter Saturation Voltage (V_CE(sat)):At I_F= 5 mA and I_C= 0.4 mA, maximum 0.35 V. Low saturation voltage is beneficial for achieving a strong logic low-level output.
• Isolation resistor (R_IO):At 500 V¹⁰The minimum is 5 x 10_DCΩ, ensuring excellent DC isolation.
• Floating capacitance (C_IO):Typical value is 0.6 pF, maximum is 1.0 pF. This low capacitance helps improve common-mode transient immunity.
• Switching time:at V_on) and turn-off time (t_offThe maximum specification for both is 25 µs. This defines the speed at which the device operates for digital signal transmission._CC= 5V, I_F= 5 mA, R_L= 5 kΩ test conditions, turn-on time (t

3. Performance Curve Analysis

The datasheet references typical optoelectronic characteristic curves. While the provided text does not detail specific charts, such curves typically illustrate the relationship between key parameters. Designers should expect to see curves describing the following:

• The relationship between CTR and forward current (I_F):Shows how the Current Transfer Ratio varies with different LED drive currents.
• CTR versus ambient temperature (T_A):Explain the temperature dependence of CTR, which typically decreases as temperature increases.
• Collector current (I_C) versus collector-emitter voltage (V_CE):A family of curves for different LED currents, showing the output characteristics of the phototransistor.
• Switch waveform:Provides test circuit and related waveforms (Figure 7) to define the conditions for measuring t_onand t_off. This typically involves a pulse generator driving an LED, and an oscilloscope monitoring the phototransistor output across a load resistor.

Analyzing these curves is crucial for optimizing circuit performance within the expected operating temperature and current range.

4. Mechanical and Packaging Information

4.1 Package Options and Dimensions

EL2514-G offers various 4-pin DIP package variants to accommodate different assembly processes:

• Standard DIP:Classic through-hole package.
• Option M:Features "wide lead bend" providing a 0.4-inch (approximately 10.16 mm) lead pitch, which may be useful for specific PCB layout or creepage distance requirements.
• Option S1:A surface-mount (SMD) pin form with a low-profile shape. It offers two tape-and-reel packaging options (TU, TD), with 1500 devices per reel.
• Option S2:Another surface-mount pin form, also with a low-profile shape, and the tape-and-reel packaging option contains 2000 devices per reel.

Detailed dimensional drawings are provided for each package type, including key dimensions such as body size, lead length, lead pitch, and standoff height. The creepage distance between the input and output sides is specified to be greater than 7.62 mm, which contributes to achieving a high isolation rating.

4.2 Pin Configuration and Polarity

The device uses a standard 4-pin DIP pin arrangement:

1. Pin 1: Anode (Input LED)
2. Pin 2: Cathode (Input LED)
3. Pin 3: Emitter (Output Phototransistor)
4. Pin 4: Collector (Output Phototransistor)

Correct orientation is crucial. Device marking includes the code "EL2514GYWWV", where EL represents the manufacturer, 2514 is the device number, G indicates halogen-free, Y is a single-digit year code, WW is a two-digit week code, and V denotes optional VDE certification.

4.3 Recommended PCB Pad Layout

For surface mount options (S1 and S2), the datasheet provides recommended pad layouts. These are reference designs intended to ensure reliable soldering and mechanical stability. The document explicitly states that these dimensions should be modified according to specific manufacturing processes and requirements, such as solder paste volume and thermal relief considerations.

5. Soldering and Assembly Guide

The soldering temperature (T_SOL) rating for this device is 260°C for a maximum of 10 seconds. This is consistent with typical lead-free reflow profiles. For through-hole packages using wave soldering, standard industry practices should be followed, taking care not to exceed the maximum body temperature of the package. The storage temperature range is -55°C to +125°C. For SMD assembly, it is recommended to store the device in moisture barrier packaging, and if the moisture exposure level is exceeded, proper baking procedures should be followed.

6. Packaging and Ordering Information

The ordering code follows the pattern: EL2514X(Y)-VG.

• X:Pin form options (S1, S2, M, or blank for standard DIP).
• Y:Tape and reel packaging options (TU, TD, or leave blank for tube).
• V:Indicates VDE safety certification (optional).
• G:Indicates halogen-free construction.

Different packaging quantities: Through-hole option has 100 devices per tube, SMD tape and reel option has 1500 or 2000 devices per reel. Detailed reel specifications are provided, including pocket dimensions (A0, B0), tape width (W), pitch (P0), and reel hub diameter, for automated placement machine programming.

7. Application Recommendations

7.1 Typical Application Scenarios

EL2514-G is very suitable for applications requiring electrical isolation, noise immunity, or level shifting. Specific applications mentioned include:

• Programmable Logic Controller (PLC):Used to isolate digital I/O modules from the central processing unit and field devices.
• System Equipment and Measuring Instruments:Isolate sensor signals or communication lines in industrial equipment.
• Electronic energy meter:Provide isolation in metering circuits to ensure safety and suppress noise.
• Telecommunication equipment:Signal isolation in data lines or power supply feedback loops.
• Power supply:Commonly used in the feedback loop of Switch-Mode Power Supplies (SMPS) to isolate the feedback signal from the secondary side from the controller on the primary side, thereby improving safety and stability.

7.2 Design Considerations

• CTR Variation:When designing the receiving circuit (e.g., comparator threshold, pull-up resistor value), ensure reliable operation across the entire CTR range of 50-200%.
• Speed and Load:Switching speed is specified with a 5 kΩ load. Using a smaller load resistor generally increases switching speed but reduces output swing and increases power consumption. Larger resistors slow the response, especially the turn-off time, due to the phototransistor's storage time.
• LED Current Limiting:Be sure to use a series resistor to limit the forward current (I_F) within the recommended operating range (typically 5-7 mA) or below the absolute maximum rating. This ensures long-term reliability and stable CTR.
• Noise Immunity:Although optocouplers provide excellent common-mode rejection, proper PCB layout should be maintained by keeping input and output traces separate and using bypass capacitors near the device pins to suppress high-frequency noise.

8. Technical Comparison and Positioning

EL2514-G distinguishes itself in the market by combining key attributes. Its high isolation voltage (5000 Vrms) and long creepage distance make it a strong candidate for applications with stringent safety requirements. The halogen-free construction meets environmental regulations and customer preferences for "green" electronics. The extensive portfolio of certifications (UL, VDE, etc.) lowers certification barriers for end products targeting global markets. While its switching speed (25 µs) is suitable for many digital isolation and power supply feedback applications, it is not positioned as an ultra-high-speed coupler for data communication; such applications require devices with nanosecond switching times. Therefore, EL2514-G is best viewed as a rugged, general-purpose optocoupler optimized for reliability, safety compliance, and moderate performance.

9. Frequently Asked Questions (Based on Technical Parameters)

Q: What does a CTR range of 50-200% mean for my circuit design?
A: This means the output current can be as low as half of the input current, or as high as twice that. Your circuit must function correctly under both extremes. For digital interfaces, this affects the selection of pull-up resistors and the input thresholds of subsequent gates or microcontrollers.

Q: Can I drive the LED directly with a voltage source?
A: No. LED is a current-driven device. You must always use a current-limiting resistor in series with the LED to set the desired I_Fand prevent overcurrent damage, even if your power supply voltage matches the typical V_F.

Q: The isolation voltage is 5000 Vrms. Does this mean I can continuously apply 5000V between the input and output?
A: No. This is the withstand voltage tested for one minute under controlled conditions. The continuous working voltage in the application should be significantly lower than this, as defined by the relevant safety standards for the end equipment.

Q: What is the difference between option S1 and S2?
A: The main differences are in the package size and tape reel size. S2 has a slightly larger body width (B0 dimension) and uses a wider tape reel (16mm for S1, 24mm for S2), allowing more devices per reel (1500 for S1, 2000 for S2). The choice depends on your PCB space constraints and the compatibility with your assembly line's feeder.

10. Practical Design Cases

Scenario: Isolate the digital signal of the microcontroller to the high-voltage section.
A microcontroller (3.3V logic) needs to send an ON/OFF signal to a circuit operating at a different and noisy high-voltage potential. The EL2514-G can be used for isolation.

Design Steps:

1. Input side:Through a current limiting resistor (R_limitConnect the microcontroller GPIO pin to the anode of the optocoupler. Calculate R_limit= (V_{CC_MCU}- V_F) / I_F. For V_{CC_MCU}=3.3V, V_F~1.2V, target I_F=5mA, then R_limit= (3.3-1.2)/0.005 = 420Ω. Use a standard 470Ω resistor. Connect the cathode to ground.
2. Output side:Connect the collector to a pull-up resistor (R_L) on an isolated high-voltage power supply (e.g., 12V). Connect the emitter to the isolated ground. R_LThe value affects speed and current. Using the 5kΩ resistor from the datasheet test conditions provides the specified switching times. The signal from the collector node can then drive the MOSFET gate on the isolated side or another logic input.
3. Layout:Physically separate the input and output sections on the PCB. Maintain a creepage distance greater than 7.62 mm according to package capability. Place a small bypass capacitor (e.g., 0.1µF) close to the device pins between the supply and ground on both sides of the coupler.

This setup prevents ground loops, blocks noise, and protects the microcontroller from voltage transients on the high-voltage side.

11. How It Works

An optocoupler is a device that uses light to transmit electrical signals between two isolated circuits. In the EL2514-G, the current applied to the input pins (1 and 2) causes an infrared light-emitting diode (LED) to emit photons. These photons pass through a transparent insulating gap (typically made of molding compound) and strike the base region of a silicon phototransistor on the output side (pins 3 and 4). The incident light generates electron-hole pairs in the base region, effectively acting as a base current. This photogenerated base current is then amplified by the transistor's gain, producing a collector current (I_C) proportional to the input LED current (I_F). The ratio I_C/I_FIt is the Current Transfer Ratio (CTR). The key point is that the only connection between the input and output is the light beam, thereby providing electrical isolation.

12. Technology Trends

The optocoupler market continues to evolve. Trends affecting devices such as the EL2514-G include:

• Ƙaruwar Haɗin kai:Haɗa tashoshi masu keɓewa da yawa tare, ko haɗa ayyuka ƙari kamar direban ƙofar ko mai ƙara kuskure a cikin fakitin guda ɗaya.
• Haɓaka masu haɗawa waɗanda ke amfani da na'urori masu gano sauri (kamar photodiodes tare da masu ƙara haɗin kai) don tallafawa ka'idojin sadarwar dijital na ƙimar Mbps (USB, CAN, RS-485).Enhancing Reliability and Lifespan:
• Focus on improving the long-term stability of CTR, which degrades over time due to LED aging, especially under high temperature and high current conditions.Stricter Environmental Compliance:
• Beyond RoHS and halogen-free, there is growing attention in the supply chain towards substances like PFAS and broader sustainability metrics.Alternative Isolation Technologies:
• While optocouplers still dominate in many applications, capacitive isolation (using SiObarrier) and magnetic isolation (using transformers) are competing in areas requiring extremely high speed, low power consumption, or high integration density. Optocouplers maintain advantages in simplicity, high common-mode transient immunity (CMTI), and established safety certifications.₂EL2514-G focuses on safety certification, environmental compliance, and robust performance, meeting the enduring needs in industrial, power, and equipment markets where these trends are crucial.

EL2514-G focuses on safety certification, environmental compliance, and robust performance, meeting the enduring needs in industrial, power, and equipment markets where these trends are crucial.