4N35FR2M Optoisolator Transistor with Base - Equivalent & Substitute Parts

Part Overview

The 4N35FR2M is a single-channel optoisolator with transistor output and base connection, rated for 7500Vpk isolation voltage. Manufactured by onsemi in 6-SMD surface mount packaging, this component provides galvanic isolation for DC input signals with transistor-based output control. The product status is obsolete, making identification of compatible substitute parts essential for ongoing design support and procurement.

Substiute Parts

4N35FR2M

onsemiIn Stock: 10024N35FR2M Datasheet

Current PartRFQ

4N35SR2M

onsemiIn Stock: 40334N35SR2M Datasheet

SimilarRFQ

4N35

onsemiIn Stock: 979644N35 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the 4N35FR2M is determined by the following critical parameters:

• Single-channel configuration with transistor output and base connection
• Isolation voltage rating (minimum 7500Vpk for direct replacement)
• Current transfer ratio of 100% @ 10mA
• Maximum output voltage of 30V
• Vce saturation of 300mV
• Turn-on/turn-off time of 2µs
• Surface mount 6-SMD package with gull wing leads
• Operating temperature range of -55°C to 100°C

The 4N35FR2M belongs to the onsemi 4N35 optoisolator family. Substitute parts must maintain electrical compatibility across isolation voltage, output characteristics, and switching performance. Package form factor and mounting type are critical for PCB layout compatibility.

Parameter Comparison

Engineering Selection Recommendations

The 4N35SR2M is the primary active substitute for the obsolete 4N35FR2M. Both components share identical surface mount 6-SMD packaging, electrical output characteristics, and switching performance. The 4N35SR2M maintains active product status with onsemi, ensuring ongoing availability and supply chain continuity. The isolation voltage rating of 4170Vrms on the 4N35SR2M is lower than the 7500Vpk specification of the 4N35FR2M; applications requiring the full 7500Vpk isolation rating must evaluate circuit requirements before substitution.

The 4N35 (6-DIP through-hole package) is electrically compatible but requires PCB redesign due to different mounting technology and package form factor. This option is suitable only when PCB layout modifications are feasible. The 4N35 is also obsolete, limiting its use as a long-term solution.

For new designs or ongoing production requiring surface mount optoisolators with transistor output and base connection, the 4N35SR2M is the recommended selection based on active product status and compliance certifications.

Frequently Asked Questions (FAQ)

Q: Can the 4N35SR2M directly replace the 4N35FR2M without PCB modifications?

A: Yes. Both components use identical 6-SMD surface mount packaging with gull wing leads, identical pin configurations, and compatible electrical characteristics. No PCB layout changes are required for package compatibility.

Q: What is the isolation voltage difference between 4N35FR2M and 4N35SR2M?

A: The 4N35FR2M is rated for 7500Vpk isolation, while the 4N35SR2M is rated for 4170Vrms isolation. Applications operating at isolation voltages below 4170Vrms can use the 4N35SR2M without circuit modification. Applications requiring the full 7500Vpk isolation rating must evaluate whether the lower rating of the substitute part meets system requirements.

Q: Why is the 4N35 (6-DIP) not recommended as a direct substitute?

A: The 4N35 uses through-hole 6-DIP packaging, which is incompatible with the surface mount 6-SMD footprint of the 4N35FR2M. PCB redesign and component placement changes are required. Additionally, the 4N35 is obsolete, making it unsuitable for long-term production support.

Q: Are there compliance or regulatory differences between the substitute parts?

A: All three parts share identical REACH status (REACH Unaffected) and ECCN classification (EAR99). The 4N35SR2M includes RoHS3 compliance certification. All parts maintain MSL 1 (Unlimited) moisture sensitivity rating.

Q: What is the minimum operating temperature difference between 4N35FR2M and 4N35SR2M?

A: The 4N35FR2M operates from -55°C to 100°C, while the 4N35SR2M operates from -40°C to 100°C. Applications requiring operation below -40°C must use the 4N35FR2M or evaluate alternative optoisolator families.

Q: Is the 4N35SR2M available in different packaging formats?

A: The 4N35SR2M is supplied in Cut Tape (CT) and Digi-Reel packaging formats. The 4N35FR2M packaging format is not specified in available data. Confirm packaging requirements with your procurement process.