5-Pin SOP High-Speed 10Mbit/s Logic Gate Photocoupler ELM453H-G Series Datasheet - Package 5-Pin SOP - Isolation Voltage 3750Vrms - English Technical Document

1. Product Overview

The ELM453H-G Series represents a family of high-speed, logic gate photocouplers (opto-isolators) designed for demanding digital isolation applications. These devices are engineered to provide reliable signal transmission while maintaining high electrical isolation between input and output circuits. The core function is to transfer digital logic signals across an isolation barrier using an infrared LED optically coupled to a high-speed photodetector and transistor amplifier.

The primary market for this component includes industrial automation, motor drive systems, fieldbus communication networks, and power supply control where noise immunity and safety isolation are critical. Its core advantages stem from its enhanced speed performance compared to conventional phototransistor couplers, achieved through a separate photodiode bias connection that reduces base-collector capacitance.

2. Technical Parameter Deep-Dive

This section provides an objective analysis of the key electrical and optical parameters specified in the datasheet.

2.1 Absolute Maximum Ratings

These ratings define the stress limits beyond which permanent damage may occur. Key limits include:

• Input Forward Current (I_F): 25 mA maximum. Exceeding this can degrade or destroy the input LED.
• Isolation Voltage (V_ISO): 3750 V_rms for 1 minute. This is a critical safety rating certifying the dielectric strength of the internal isolation barrier, tested with pins 1 & 3 shorted on one side and pins 4, 5 & 6 shorted on the other.
• Operating Temperature (T_OPR): -40 to +125 °C. This wide range ensures reliable operation in harsh industrial environments.
• Soldering Temperature (T_SOL): 260 °C for 10 seconds, compliant with typical lead-free reflow profiles.

2.2 Electrical Characteristics

The guaranteed performance parameters under specified test conditions.

2.2.1 Input Characteristics

• Forward Voltage (V_F): Typically 1.4V, with a maximum of 1.8V at I_F=16mA. This is used to calculate the required current-limiting resistor for the LED driver circuit.
• Input Capacitance (C_IN): Typically 70 pF. A lower capacitance can contribute to better high-frequency performance on the input side.

2.2.2 Output & Transfer Characteristics

• Low-Level Output Voltage (V_OL): Maximum 0.4V at I_F=16mA, I_O=3mA, V_CC=4.5V. This defines the output logic '0' level under load.
• Current Transfer Ratio (CTR): Minimum 20% under the same test conditions. CTR is the ratio of output transistor current to input LED current. A minimum guarantee ensures sufficient output drive capability.
• High-Level Output Current (I_OH): Very low leakage current (max 5 µA at 25°C) when the LED is off, ensuring a clean logic '1' output.

2.3 Switching Characteristics

These parameters define the device's speed and noise immunity, crucial for data transmission.

• Propagation Delay (T_PHL, T_PLH): Typical 0.35 µs (low) and 0.45 µs (high), with a maximum of 1.0 µs. This allows for signal transmission rates up to 1Mbit/s, though the title suggests 10Mbit/s capability for the logic gate version.
• Common Mode Transient Immunity (CM_H, CM_L): Minimum 10 kV/µs. This is a vital parameter indicating the device's ability to reject fast voltage transients (noise) that appear equally on both sides of the isolation barrier. High CMTI prevents false output switching in noisy environments like motor drives.

3. Performance Curve Analysis

The datasheet references typical electro-optical characteristic curves. While not displayed in the provided text, these curves typically illustrate relationships critical for design:

• Current Transfer Ratio (CTR) vs. Forward Current (I_F): Shows how efficiency varies with drive current, helping optimize the operating point.
• CTR vs. Ambient Temperature (T_A): Demonstrates the derating of CTR with increasing temperature, essential for high-temperature operation.
• Propagation Delay vs. Load Resistor (R_L): Shows the trade-off between switching speed and output drive capability.
• Forward Voltage vs. Temperature: Important for thermal management of the input circuit.

Designers should consult the full datasheet graphs to understand these non-linear relationships for robust circuit design.

4. Mechanical & Package Information

4.1 Package Dimension

The device is housed in a standard 5-pin Small Outline Package (SOP). The detailed mechanical drawing provides exact dimensions for length, width, height, lead pitch, and standoff. This information is critical for PCB footprint design and ensuring proper clearance.

4.2 Recommended Pad Layout

A suggested surface-mount pad layout is provided. The datasheet correctly notes that this is a reference design and should be modified based on individual manufacturing processes (e.g., solder paste type, reflow profile). Adherence to IPC standards is recommended for final pad design.

4.3 Polarity Identification & Device Marking

Pin Configuration:

1. Anode (Input LED +)
2. No Connection / Internal
3. Cathode (Input LED -)
4. GND (Output Ground)
5. V_OUT (Output Signal)
6. V_CC (Output Supply Voltage)

Device Marking: The top of the package is marked with "EL" (manufacturer code), "M453H" (device number), a 1-digit year code (Y), a 2-digit week code (WW), and an optional "V" for VDE-approved versions. This allows for traceability.

5. Soldering & Assembly Guidelines

Reflow Soldering: The component is rated for a maximum soldering temperature of 260°C for 10 seconds. This aligns with standard lead-free reflow profiles (IPC/JEDEC J-STD-020). The peak temperature and time above liquidus must be controlled to prevent package damage.

Storage Conditions: The storage temperature range is -55 to +125 °C. Moisture Sensitivity Level (MSL) information, critical for surface-mount devices, should be verified from the full datasheet or packaging. Standard precautions for baking moisture-absorbed components before reflow should be followed if applicable.

6. Packaging & Ordering Information

6.1 Ordering Part Number

The part number follows the structure: ELM453H(Z)-VG

• Z: Tape and Reel Option. 'None' for tube (100 units), 'TA' or 'TB' for different reel orientations (3000 units/reel).
• V: Denotes VDE certification is included.
• G: Indicates Halogen-Free material composition.

6.2 Tape and Reel Specifications

Detailed carrier tape dimensions (width, pocket size, pitch) and reel specifications are provided for automated pick-and-place assembly. Options TA and TB differ in the orientation of the component within the tape, affecting the feed direction from the reel.

7. Application Suggestions

7.1 Typical Application Circuits

Line Receiver / Digital Signal Isolation: The device is ideal for isolating RS-485, CAN, or other serial data lines in industrial networks. The high CMTI protects against ground potential differences and noise.

Gate Drive Isolation in Motor Drives: Used to isolate the low-voltage control signal from the high-voltage, noisy gate driver circuit for IGBTs or MOSFETs. The high isolation voltage (3750Vrms) and speed are key here.

Logic Ground Isolation: Separating digital grounds between subsystems (e.g., between a sensitive analog sensor interface and a noisy microcontroller) to prevent ground loops and noise coupling.

7.2 Design Considerations

• Input Current Limiting: An external resistor must be used to set the LED forward current (I_F), typically around 16mA for guaranteed parameters. The resistor value is R_LIMIT = (V_DRIVE - V_F) / I_F.
• Output Pull-Up Resistor: A pull-up resistor (R_L) is required on the output (pin 5 to V_CC). Its value affects switching speed (lower R_L = faster, but higher current) and logic high level. The test condition uses 1.9 kΩ.
• Power Supply Decoupling: Place a 0.1 µF ceramic capacitor close to pins 4 (GND) and 6 (V_CC) to ensure stable operation and minimize switching noise.
• Creepage and Clearance: On the PCB, maintain adequate creepage and clearance distances between the input and output circuits (including traces and components) to preserve the high-voltage isolation rating. Follow relevant safety standards (e.g., IEC 61010-1).

8. Technical Comparison & Differentiation

The ELM453H-G's primary differentiation from standard phototransistor couplers is its speed. By providing a separate base connection (via the integrated photodiode) to bias the output transistor, it drastically reduces the Miller capacitance effect that slows down conventional phototransistors. This makes it suitable for digital data transmission in the 1Mbit/s to 10Mbit/s range, whereas standard devices are often limited to below 100 kbit/s.

Furthermore, its comprehensive suite of international safety certifications (UL, cUL, VDE, SEMKO, etc.) and compliance with halogen-free, RoHS, and REACH regulations make it a preferred choice for global markets with strict environmental and safety requirements.

9. Frequently Asked Questions (Based on Technical Parameters)

Q: What is the maximum data rate this photocoupler can support?
A: Based on the maximum propagation delay of 1.0 µs, the device can reliably support data rates of at least 1 Mbit/s. The 10 Mbit/s reference in the title suggests optimized performance or a specific version; actual maximum rate depends on the circuit design (R_L, I_F) and should be verified with scope measurements for critical applications.

Q: How do I ensure the high isolation rating is maintained in my design?
A: The device's internal construction provides the isolation. To maintain it on the PCB, you must ensure sufficient physical distance (creepage/clearance) between all conductive elements (traces, pads, components) associated with the input side (pins 1,2,3) and the output side (pins 4,5,6). Follow PCB layout guidelines for reinforced insulation based on the working voltage.

Q: Can I use this to isolate analog signals?
A: While listed for analog signal ground isolation, it is fundamentally a digital (logic gate) device with non-linear CTR. It is not ideal for linear analog signal isolation. For that purpose, a dedicated linear optocoupler or an isolation amplifier would be more appropriate.

10. Practical Use Case

Scenario: Isolated SPI Communication in a Motor Control Unit.
A microcontroller on a 3.3V control board needs to send configuration data via SPI to an ADC located near a high-power motor phase. The ground potentials are noisy and different. An ELM453H-G can be used to isolate the SPI clock (SCK) and chip select (CS) lines. The microcontroller GPIO drives the LED via a current-limiting resistor. The output pin (5) is pulled up to the ADC's 5V supply through a 2.2kΩ resistor, providing a clean, isolated logic signal. The high CMTI ensures the SPI signals are not corrupted by the motor's switching noise.

11. Operating Principle

The device operates on the principle of optical coupling. An electrical current applied to the input Infrared Emitting Diode (IRED) causes it to emit light. This light traverses a transparent isolation barrier (typically a molded silicone or polymer) and strikes a photodiode within the integrated detector chip. The photodiode current is amplified and processed by a transistor stage to produce a corresponding digital output signal (sinking current to ground when active). The complete electrical isolation is achieved because the signal is transferred by light, with no electrical conduction path across the barrier.

12. Industry Trends

The trend in signal isolation is towards higher speeds, lower power consumption, smaller packages, and integration of multiple channels in a single package. While standalone photocouplers like the ELM453H-G remain vital for their robustness, high voltage capability, and simplicity, newer technologies like capacitive isolators and giant magnetoresistance (GMR) isolators are competing in applications requiring very high data rates (>100 Mbit/s) or enhanced reliability in extreme magnetic fields. However, optical coupling continues to dominate in applications requiring very high working voltage isolation, proven long-term reliability, and immunity to magnetic interference.