IL221AT Optoisolator Equivalent & Substitute Parts

Part Overview

The IL221AT is an optoisolator with Darlington output and base connection, manufactured by Vishay Semiconductor Opto Division. This component provides 4000Vrms isolation in a single-channel configuration with 8-SOIC surface mount packaging. The part is currently active in production with 2536 units in stock. Equivalent and substitute parts are identified to support design flexibility, inventory management, and supply chain continuity for applications requiring optoisolation functionality.

Substiute Parts

IL221AT

Vishay Semiconductor Opto DivisionIn Stock: 2554IL221AT Datasheet

Current PartRFQ

MOC223M

onsemiIn Stock: 13587MOC223M Datasheet

MFR RecommendedRFQ

MOC223R2M

onsemiIn Stock: 5998MOC223R2M Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the IL221AT are identified based on the following critical parameters that determine functional compatibility:

• Package / Case: 8-SOIC (0.154", 3.90mm Width) — mechanical and electrical interface compatibility
• Output Type: Darlington with Base — functional output configuration
• Number of Channels: 1 — single-channel isolation requirement
• Voltage - Output (Max): 30V — maximum output voltage rating
• Vce Saturation (Max): 1V — saturation voltage specification
• Mounting Type: Surface Mount — PCB assembly compatibility
• Input Type: DC — input signal type

The substitute parts MOC223M and MOC223R2M, both manufactured by onsemi, share identical mechanical packaging, output configuration, and key electrical parameters with the IL221AT. The primary difference is the isolation voltage rating (2500Vrms versus 4000Vrms), which represents a lower isolation specification. Both substitute parts maintain compatibility with the 8-SOIC package footprint and surface mount assembly process.

Parameter Comparison

Engineering Selection Recommendations

Both MOC223M and MOC223R2M are active production parts with ROHS3 compliance and unlimited moisture sensitivity rating, matching the environmental and regulatory requirements of the IL221AT. The primary selection criterion between these substitute parts is packaging format: MOC223M is supplied in Tube packaging, while MOC223R2M is supplied in Cut Tape (CT) & Digi-Reel® format. Selection between these two should be based on procurement and assembly line requirements.

The isolation voltage difference (2500Vrms for substitutes versus 4000Vrms for IL221AT) must be evaluated against application requirements. Applications requiring 4000Vrms isolation cannot use these substitutes. Applications with 2500Vrms isolation requirements or lower can utilize either substitute part.

Frequently Asked Questions (FAQ)

Q: Can MOC223M or MOC223R2M be used as direct replacements for IL221AT?

A: Both parts share identical 8-SOIC packaging, Darlington with Base output configuration, and key electrical parameters including 30V maximum output voltage and 1V saturation voltage. The primary difference is isolation voltage rating: IL221AT provides 4000Vrms while MOC223M and MOC223R2M provide 2500Vrms. Direct substitution is possible only if the application does not require 4000Vrms isolation.

Q: What is the difference between MOC223M and MOC223R2M?

A: Both parts are electrically identical with 2500Vrms isolation, identical electrical specifications, and the same 8-SOIC package. The difference is packaging format: MOC223M is supplied in Tube, while MOC223R2M is supplied in Cut Tape (CT) & Digi-Reel® format. Selection depends on procurement and assembly process requirements.

Q: Are there any temperature range considerations when substituting?

A: IL221AT operates from -55°C to 100°C, while MOC223M and MOC223R2M operate from -40°C to 100°C. Applications requiring operation below -40°C must use IL221AT. Applications within the -40°C to 100°C range can use either substitute part.

Q: Do the substitute parts have the same current transfer ratio?

A: No. IL221AT specifies 100% minimum current transfer ratio at 1mA, while MOC223M and MOC223R2M specify 500% minimum at 1mA. The higher current transfer ratio of the substitute parts indicates improved optical coupling efficiency.

Q: Are all three parts RoHS compliant?

A: Yes. IL221AT, MOC223M, and MOC223R2M are all ROHS3 compliant with MSL rating of 1 (Unlimited), meeting the same environmental and regulatory requirements.