IL4108-X009 Optoisolator Equivalent & Substitute Parts

Part Overview

The IL4108-X009 is an active optoisolator with triac output manufactured by Vishay Semiconductor Opto Division. This component provides 5300Vrms isolation with zero-crossing detection, designed for AC switching applications requiring galvanic isolation. The part is in active production status with 738 units currently in stock. Substitute parts are necessary to address supply chain flexibility, alternative packaging formats, and inventory availability across multiple manufacturers while maintaining functional compatibility.

Substiute Parts

IL4108-X009

Vishay Semiconductor Opto DivisionIn Stock: 810IL4108-X009 Datasheet

Current PartRFQ

FOD4108S

Fairchild SemiconductorIn Stock: 4184FOD4108S Datasheet

MFR RecommendedRFQ

FOD4108SD

onsemiIn Stock: 1923FOD4108SD Datasheet

MFR RecommendedRFQ

FOD4118S

onsemiIn Stock: 1403FOD4118S Datasheet

MFR RecommendedRFQ

FOD4118SD

onsemiIn Stock: 3384FOD4118SD Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the IL4108-X009 is determined by the following critical parameters:

Primary Compatibility Criteria:

• Triac output configuration
• Zero-crossing detection circuit
• Single channel architecture
• 6-SMD surface mount package
• Operating temperature range -55°C to 100°C
• Off-state voltage rating of 800V
• Static dV/dt minimum of 10kV/µs

Acceptable Variation:

• Isolation voltage: 5000Vrms to 5300Vrms (minimum 5000Vrms required)
• LED trigger current (Ift): 1.3mA to 2mA
• Turn-on time: 35µs to 60µs
• Forward voltage (Vf): 1.16V to 1.25V
• DC forward current (If): 30mA to 60mA

All four substitute parts meet these criteria across electrical and mechanical specifications. Packaging format (Tube, Bulk, or Tape & Reel) represents a secondary consideration for supply chain sourcing and does not affect functional compatibility.

Parameter Comparison

Engineering Selection Recommendations

All four substitute parts maintain active product status and meet the core functional requirements for triac output optoisolator applications with zero-crossing detection. Selection between IL4108-X009 and its substitutes should be based on the following factors:

Isolation Voltage Consideration: The IL4108-X009 provides 5300Vrms isolation, while all substitute parts provide 5000Vrms. Applications requiring the higher isolation rating must retain the IL4108-X009. Applications with 5000Vrms isolation requirements can utilize any substitute part.

LED Trigger Current: FOD4118S and FOD4118SD feature a lower LED trigger current maximum of 1.3mA compared to 2mA for IL4108-X009, FOD4108S, and FOD4108SD. This represents improved input efficiency and may be advantageous in current-limited driver circuits.

Turn-On Time: IL4108-X009 specifies 35µs turn-on time, while all substitutes specify 60µs. Applications with stringent timing requirements should verify compatibility with the longer switching delay.

Compliance and Certifications: All parts maintain active status and carry CSA approval. FOD4108SD, FOD4118S, and FOD4118SD carry explicit ROHS3 compliance documentation. All parts carry EAR99 ECCN classification.

Packaging and Inventory: FOD4108SD and FOD4118SD are available in Tape & Reel format suitable for automated assembly. FOD4108S is available in Bulk format. FOD4118S is available in Tube format matching the IL4108-X009 packaging. Inventory availability ranges from 1381 to 4156 units across substitute options.

Frequently Asked Questions (FAQ)

Q: Can FOD4108S, FOD4108SD, FOD4118S, and FOD4118SD be used interchangeably with IL4108-X009?

A: These parts are functionally compatible substitutes when the application isolation voltage requirement does not exceed 5000Vrms. All maintain identical triac output configuration, zero-crossing detection, single-channel architecture, 6-SMD package, and operating temperature range. Differences in LED trigger current and turn-on time must be evaluated against specific circuit requirements.

Q: What is the difference between FOD4108 and FOD4118 base part numbers?

A: The primary difference is LED trigger current specification. FOD4108 series specifies 2mA maximum trigger current, while FOD4118 series specifies 1.3mA maximum trigger current. Both maintain identical isolation voltage, output type, zero-crossing detection, and package configuration.

Q: Does packaging format (Tube, Bulk, Tape & Reel) affect electrical performance?

A: No. Packaging format is a supply chain and assembly consideration only. Tube, Bulk, and Tape & Reel formats contain electrically identical components. Selection should be based on assembly process requirements and inventory management practices.

Q: Are all substitute parts ROHS3 compliant?

A: FOD4108SD, FOD4118S, and FOD4118SD carry explicit ROHS3 compliance documentation. FOD4108S does not specify RoHS status in available documentation. Applications requiring verified ROHS3 compliance should select from FOD4108SD, FOD4118S, or FOD4118SD.

Q: What is the significance of the 35µs versus 60µs turn-on time difference?

A: IL4108-X009 specifies 35µs turn-on time while all substitute parts specify 60µs. This represents a 71% increase in switching delay. Applications with timing-critical AC switching requirements must verify that the longer turn-on time remains acceptable for the intended circuit function.

Q: Can I use a substitute part with lower isolation voltage in a 5300Vrms application?

A: No. Isolation voltage is a critical safety parameter. Applications requiring 5300Vrms isolation must use IL4108-X009. Substitutes rated for 5000Vrms are not suitable for higher isolation voltage requirements.