4N35TM Optoisolator Equivalent & Substitute Parts

Part Overview

The 4N35TM is an optoisolator transistor with base output manufactured by onsemi, designed for high-voltage isolation applications. It features 7500Vpk isolation voltage in a 6-DIP package with a single channel transistor output configuration. The 4N35TM is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement.

Substiute Parts

4N35TM

onsemiIn Stock: 10304N35TM Datasheet

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4N35TVM

onsemiIn Stock: 43264N35TVM Datasheet

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4N35-W00E

Broadcom LimitedIn Stock: 10334N35-W00E Datasheet

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4N35-W60E

Broadcom LimitedIn Stock: 43604N35-W60E Datasheet

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4N35G

Isocom Components 2004 LTDIn Stock: 12254N35G Datasheet

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4N35M

onsemiIn Stock: 226464N35M Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the 4N35TM is determined by the following critical parameters:

• Package Type: All substitutes must use 6-DIP through-hole mounting to ensure mechanical compatibility
• Output Configuration: All substitutes must feature transistor output with base connection
• Number of Channels: Single channel configuration required
• Input Type: DC input required
• Isolation Voltage: Substitutes with equal or higher isolation voltage rating are acceptable
• Current Transfer Ratio: Minimum 100% @ 10mA required
• Output Voltage Rating: Maximum 30V output voltage required
• Vce Saturation: Maximum 300mV required
• Forward Voltage: Typical 1.18V to 1.3V range acceptable

Substitutes are grouped by isolation voltage rating, as this is the primary differentiator among available alternatives while maintaining all other critical electrical and mechanical parameters.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Active Status, Highest Isolation Voltage)

4N35G (Isocom Components 2004 LTD) is the preferred substitute when isolation voltage requirements are critical. It provides 5300Vrms isolation, which approaches the original 7500Vpk specification while maintaining all electrical parameters. This part is active and ROHS3 compliant.

Secondary Substitutes (Active Status, Moderate Isolation Voltage)

4N35TVM and 4N35M (both onsemi) provide 4170Vrms isolation voltage with identical electrical characteristics to the main part. Both are active products with ROHS3 compliance. 4N35TVM is available in standard 6-DIP (0.400", 10.16mm) packaging, while 4N35M uses a narrower 6-DIP (0.300", 7.62mm) package.

Alternative Substitutes (Active Status, Lower Isolation Voltage)

4N35-W00E and 4N35-W60E (both Broadcom Limited) provide 3550Vrms isolation voltage. These parts are suitable for applications where lower isolation voltage is acceptable. Both offer extended operating temperature range (-55°C to 100°C) and are ROHS3 compliant.

Compliance Considerations

All active substitute parts are ROHS3 compliant and REACH unaffected. The original 4N35TM is obsolete; selection of an active substitute ensures long-term availability and regulatory compliance.

Frequently Asked Questions (FAQ)

Q: Can 4N35-W00E or 4N35-W60E be used as direct replacements for 4N35TM?

A: These parts are electrically compatible substitutes with identical output configuration, current transfer ratio, and saturation characteristics. However, their isolation voltage rating (3550Vrms) is lower than the original 4N35TM (7500Vpk). Use these substitutes only if your application isolation voltage requirement is 3550Vrms or lower.

Q: What is the difference between 4N35TVM and 4N35M?

A: Both parts are manufactured by onsemi with identical electrical specifications and 4170Vrms isolation voltage. The primary difference is package size: 4N35TVM uses standard 6-DIP (0.400", 10.16mm) while 4N35M uses narrower 6-DIP (0.300", 7.62mm). Select based on PCB layout requirements.

Q: Is 4N35G suitable for high-isolation applications?

A: Yes. 4N35G provides 5300Vrms isolation voltage, which is the closest match to the original 4N35TM specification among active substitutes. It maintains all required electrical parameters and is ROHS3 compliant.

Q: Are all substitutes pin-compatible with 4N35TM?

A: All substitutes use 6-DIP through-hole packaging with transistor output and base connection. However, 4N35M uses a narrower package body (0.300" vs 0.400"). Verify PCB footprint compatibility before selection.

Q: What is the operating temperature range difference between substitutes?

A: 4N35TM, 4N35TVM, and 4N35M operate from -40°C to 100°C. 4N35-W00E, 4N35-W60E, and 4N35G offer extended range from -55°C to 100°C. Select based on your application temperature requirements.

Q: Why is 4N35TM listed as obsolete?

A: The 4N35TM is no longer in active production. Multiple active alternatives with equivalent or superior specifications are available from onsemi, Broadcom Limited, and Isocom Components 2004 LTD to support ongoing designs.