4N35W Optoisolator Equivalent & Substitute Parts

Part Overview

The 4N35W is an optoisolator transistor with base output manufactured by onsemi, rated for 5300Vrms isolation voltage in a 6-DIP through-hole package. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement. The 4N35W provides single-channel DC input optoisolation with transistor output including base connection, suitable for applications requiring galvanic isolation in industrial and consumer electronics.

Substiute Parts

4N35W

onsemiIn Stock: 11154N35W 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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4N35-X006

Vishay Semiconductor Opto DivisionIn Stock: 37354N35-X006 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 for the 4N35W is determined by the following critical parameters:

• Package compatibility: 6-DIP through-hole form factor (0.400", 10.16mm)
• Isolation voltage: Minimum 5000Vrms to maintain equivalent isolation performance
• Output configuration: Transistor with base output for direct pin compatibility
• Input type: DC input matching the original design
• Operating temperature range: -55°C minimum to support industrial applications
• Current transfer ratio: 100% @ 10mA minimum specification
• Vce saturation: 300mV maximum for switching performance

Substitute parts are grouped into two categories based on isolation voltage capability:

Group A (High Isolation - 5000Vrms and above): Parts maintaining or exceeding the original 5300Vrms isolation specification, suitable for direct replacement in applications requiring maximum isolation margin.

Group B (Reduced Isolation - 3550Vrms): Parts with lower isolation voltage, suitable only for applications where 3550Vrms isolation meets system requirements.

Parameter Comparison

Engineering Selection Recommendations

4N35G (Isocom Components 2004 LTD) — Recommended primary substitute. Matches the original 5300Vrms isolation voltage specification, maintains identical 100% CTR @ 10mA performance, and provides equivalent 2µs switching times. Active product status with ROHS3 compliance and unlimited MSL rating ensures long-term availability and environmental compliance.

4N35M (onsemi) — Recommended secondary substitute from the original manufacturer. Provides 4170Vrms isolation voltage with active product status and ROHS3 compliance. Operating temperature range reduced to -40°C minimum; suitable for applications not requiring -55°C operation. Identical 2µs switching performance and 300mV Vce saturation.

4N35-X006 (Vishay Semiconductor Opto Division) — Alternative for applications where 5000Vrms isolation meets system requirements. Active product status with ROHS3 compliance. Note: 10µs switching time is slower than the original 2µs specification; output current limited to 50mA versus 100mA on the main part.

4N35-W60E and 4N35-W00E (Broadcom Limited) — Suitable only for applications where 3550Vrms isolation is acceptable. Both parts are active with ROHS3 compliance and identical 100mA output current capability. Rise/fall times of 3µs represent a compromise between the original 2µs and the 10µs of alternative sources.

4N35M Package Consideration — The 4N35M uses a 6-DIP (0.300", 7.62mm) package versus the standard 0.400" (10.16mm) package of all other substitutes. Verify PCB footprint compatibility before selection.

Frequently Asked Questions (FAQ)

Q: Can I use 4N35-W60E or 4N35-W00E as direct replacements for the 4N35W?

A: These parts are electrically compatible in terms of package, pin configuration, and output type. However, isolation voltage is reduced from 5300Vrms to 3550Vrms. Use only if your application design margin permits 3550Vrms isolation. Both parts are active products with current availability.

Q: What is the key difference between 4N35G and 4N35M?

A: Both maintain high isolation voltage (5300Vrms and 4170Vrms respectively) and 2µs switching performance. The primary difference is operating temperature range: 4N35G supports -55°C to 100°C, while 4N35M supports -40°C to 100°C. Select 4N35G for applications requiring full -55°C operation.

Q: Why does 4N35-X006 have slower switching time (10µs) than the original?

A: The 10µs turn-on/turn-off time is a characteristic of the Vishay design. This part is suitable for applications where switching speed is not critical. Verify timing requirements in your circuit before selection.

Q: Is the 4N35M package difference (0.300" vs 0.400") a problem?

A: The 4N35M uses a narrower 6-DIP package. This affects PCB footprint compatibility. Verify your PCB layout accommodates the 0.300" (7.62mm) package width before committing to this substitute.

Q: Are all substitute parts RoHS compliant?

A: Yes. All active substitute parts (4N35G, 4N35M, 4N35-W60E, 4N35-W00E, 4N35-X006) carry ROHS3 compliance certification. The original 4N35W does not list RoHS status.

Q: Which substitute has the best current output capability?

A: 4N35-W60E, 4N35-W00E, and 4N35G all support 100mA output current, matching the original 4N35W specification. The 4N35-X006 is limited to 50mA output current.

Q: Can I mix different substitute parts in the same design?

A: All substitutes maintain the same 6-DIP pin configuration and transistor-with-base output type, allowing functional interchangeability. However, verify isolation voltage and switching time requirements for your specific application before mixing parts in production.