EL354 Optoisolator Equivalent & Substitute Parts

Part Overview

The EL354 is a 3.75kV isolation optoisolator with transistor output manufactured by Everlight Electronics Co Ltd. This component is classified as obsolete, making equivalent substitutes necessary for ongoing design support and procurement. The EL354 provides single-channel optical isolation suitable for AC and DC input applications with a 4-SOP surface mount package configuration.

Substiute Parts

EL354

Everlight Electronics Co LtdIn Stock: 16496EL354 Datasheet

Current PartRFQ

LTV-354T

Lite-On Inc.In Stock: 90406LTV-354T Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the EL354 optoisolator is determined by the following critical electrical and mechanical parameters:

Isolation Voltage: The substitute must maintain 3750Vrms isolation rating to ensure equivalent safety and performance in high-voltage isolation applications.

Number of Channels: Single-channel configuration is required for direct functional replacement.

Output Type: Transistor output configuration must be preserved for circuit compatibility.

Package Configuration: 4-SOP surface mount package with gull wing leads ensures mechanical and thermal compatibility with existing PCB layouts.

Current Transfer Ratio Range: The substitute must support the minimum 20% CTR specification. Maximum CTR may vary within acceptable limits for the application.

Input Type Compatibility: AC and DC input capability must be maintained.

Forward Voltage and Current Ratings: The substitute must support the specified Vf (1.2V typical) and If (50mA maximum) parameters for LED input stage compatibility.

Vce Saturation: The 200mV maximum specification must be met for output stage performance.

Operating Temperature Range: The substitute must cover the required temperature envelope for the application environment.

Parameter Comparison

Engineering Selection Recommendations

LTV-354T as Primary Substitute:

The LTV-354T manufactured by Lite-On Inc. is the direct functional equivalent for the obsolete EL354. Both components share identical isolation voltage (3750Vrms), channel count (1), output type (transistor), package configuration (4-SOP), and critical electrical parameters including forward voltage, forward current, and saturation voltage specifications.

The LTV-354T is classified as Active product status, ensuring long-term availability and supply chain continuity. The substitute demonstrates ROHS3 compliance, providing enhanced environmental and regulatory alignment compared to the EL354.

Parameter Differences:

The LTV-354T exhibits a higher maximum current transfer ratio (400% versus 300%), which does not compromise substitution as the minimum CTR specification (20% @ 1mA) is identical. The reduced maximum output voltage (35V versus 80V) requires circuit-level evaluation to confirm compatibility with existing load requirements. The extended upper operating temperature limit (110°C versus 100°C) provides improved thermal margin.

Compliance Considerations:

Both components maintain REACH Unaffected status and unlimited moisture sensitivity classification (MSL 1), ensuring equivalent handling and storage requirements. The LTV-354T's ROHS3 compliance supports modern procurement and environmental standards.

Frequently Asked Questions (FAQ)

Q: Can the LTV-354T directly replace the EL354 in existing designs?

A: The LTV-354T is functionally equivalent for applications where the output voltage requirement does not exceed 35V. The EL354 supports up to 80V output, so designs utilizing the full 80V capability require circuit modification or alternative substitutes. All other electrical parameters, isolation voltage, package configuration, and thermal characteristics are compatible.

Q: What is the significance of the different maximum current transfer ratios?

A: The EL354 specifies 300% maximum CTR while the LTV-354T specifies 400% maximum CTR. Both components meet the 20% minimum CTR requirement. Higher maximum CTR indicates improved optical coupling efficiency in the LTV-354T and does not create incompatibility. Circuit designs relying on specific CTR matching should account for the wider tolerance range.

Q: Are there temperature range differences that affect substitution?

A: The EL354 operates from -55°C to 100°C while the LTV-354T operates from -30°C to 110°C. For applications requiring the full -55°C lower temperature limit, the LTV-354T does not provide equivalent coverage. For standard industrial temperature ranges (-30°C to 85°C), the LTV-354T provides equivalent or superior performance.

Q: How do the package specifications compare?

A: Both components use 4-SOP surface mount packages with gull wing leads and 2.54mm pitch. The packages are mechanically and electrically compatible for PCB layout purposes. The LTV-354T is available in Cut Tape and Digi-Reel packaging options, providing flexible procurement formats.

Q: What compliance certifications should be verified for new designs?

A: Both the EL354 and LTV-354T maintain REACH Unaffected status and MSL 1 (unlimited) moisture sensitivity classification. The LTV-354T adds ROHS3 compliance, which is advantageous for modern applications subject to environmental regulations. Verify specific compliance requirements for your application and regional standards.

Q: Is the LTV-354T the only available substitute?

A: The LTV-354T is the primary direct equivalent. The EL354 datasheet references additional substitutes including HMHAA280V, HCPL-354-000E, FODM2705R2, FODM2705, and HCPL-354-06AE. These alternatives may have different electrical characteristics and require individual parameter verification for specific applications.