IL4118 Optoisolator Triac Output Equivalent & Substitute Parts

Part Overview

The IL4118 is an optoisolator with triac output manufactured by Vishay Semiconductor Opto Division. This component provides galvanic isolation up to 5300Vrms with a single-channel triac output and integrated zero-crossing circuit. The part is currently active in production with 29,100 units in stock. Substitute parts may be required due to supply constraints, regional availability, or design flexibility in applications where electrical parameters fall within acceptable tolerance ranges.

Substiute Parts

IL4118

Vishay Semiconductor Opto DivisionIn Stock: 29173IL4118 Datasheet

Current PartRFQ

FOD4108

onsemiIn Stock: 2092FOD4108 Datasheet

MFR RecommendedRFQ

FOD4118

onsemiIn Stock: 1606FOD4118 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the IL4118 are qualified based on the following critical parameters:

• Output Type: Triac output configuration
• Package / Case: 6-DIP (0.300", 7.62mm) form factor for direct pin-compatible replacement
• Mounting Type: Through Hole technology
• Zero Crossing Circuit: Integrated zero-crossing detection
• Voltage - Isolation: Minimum 5000Vrms (IL4118 specifies 5300Vrms; substitutes at 5000Vrms remain within acceptable isolation margins for most applications)
• Number of Channels: Single channel
• Operating Temperature Range: -55°C ~ 100°C
• Product Status: Active production status
• Compliance: ROHS3 compliant, REACH unaffected

The FOD4108 and FOD4118 (both onsemi) meet these substitution criteria with compatible electrical and mechanical specifications.

Parameter Comparison

Engineering Selection Recommendations

FOD4118 (onsemi) is the primary substitute for IL4118. Both parts share identical LED trigger current specifications (1.3mA maximum), matching input-side performance. The FOD4118 operates at 5000Vrms isolation versus the IL4118's 5300Vrms; this 300Vrms difference remains within acceptable margins for applications designed for the IL4118. Both parts maintain identical off-state voltage (800V), temperature range (-55°C ~ 100°C), and package configuration. onsemi's FOD4118 holds CSA and UL approvals, providing regulatory coverage for most industrial applications.

FOD4108 (onsemi) serves as a secondary substitute where higher LED trigger current tolerance is acceptable. The FOD4108 specifies 2mA maximum trigger current compared to IL4118's 1.3mA, requiring circuit verification to confirm adequate drive current availability. The FOD4108 shares identical isolation voltage (5000Vrms), off-state voltage (800V), and package form factor. This part is suitable for applications with relaxed input-side current requirements.

All three parts maintain active production status, ROHS3 compliance, and REACH unaffected status, ensuring long-term availability and regulatory alignment.

Frequently Asked Questions (FAQ)

Q: Can FOD4118 directly replace IL4118 in existing designs?

A: Yes. The FOD4118 is pin-compatible in the 6-DIP package and shares the same LED trigger current specification (1.3mA). The isolation voltage difference (5000Vrms vs. 5300Vrms) does not prevent substitution in applications designed for the IL4118, as the lower rating remains within standard isolation margins for triac optoisolator applications.

Q: What is the key difference between FOD4108 and FOD4118?

A: The primary difference is LED trigger current. FOD4108 specifies 2mA maximum, while FOD4118 specifies 1.3mA maximum. Both share identical isolation voltage (5000Vrms), off-state voltage (800V), and package configuration. Selection depends on available input drive current in the application circuit.

Q: Are all three parts mechanically compatible?

A: Yes. IL4118, FOD4108, and FOD4118 all use the 6-DIP (0.300", 7.62mm) through-hole package, enabling direct mechanical substitution on PCBs designed for this form factor.

Q: What certifications apply to substitute parts?

A: FOD4108 and FOD4118 hold CSA and UL approvals. IL4118 holds BSI, CSA, cUR, FIMKO, and UR approvals. Application requirements determine which certification set is necessary.

Q: Does isolation voltage difference affect circuit performance?

A: The IL4118's 5300Vrms isolation exceeds the FOD4108 and FOD4118 specifications at 5000Vrms. For applications requiring maximum isolation margin, IL4118 is preferred. For standard industrial isolation requirements, the 5000Vrms rating of onsemi parts is sufficient.

Q: Are turn-on time differences significant?

A: IL4118 specifies 35µs turn-on time; FOD4108 and FOD4118 specify 60µs. Applications with strict timing requirements should verify that 60µs turn-on time meets system performance specifications before substitution.