4N28FR2VM Equivalent & Substitute Parts

Part Overview

The 4N28FR2VM is an optoisolator transistor with base output manufactured by onsemi, designed for high-voltage isolation applications requiring 7500Vpk isolation rating. This component integrates a photodiode input stage with a transistor output stage including base connection, enabling flexible circuit design in isolated switching and signal transmission applications.

The 4N28FR2VM is classified as obsolete. Identifying suitable substitute parts is necessary to maintain design continuity, ensure supply chain reliability, and support ongoing production requirements for systems utilizing this optoisolator topology.

Substiute Parts

4N28FR2VM

onsemiIn Stock: 9764N28FR2VM Datasheet

Current PartRFQ

4N28SR2VM

onsemiIn Stock: 12994N28SR2VM Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 4N28FR2VM is determined by the following critical parameters:

• Isolation Voltage Rating: The substitute must maintain isolation voltage capability at or above the application requirement. The 4N28FR2VM specifies 7500Vpk isolation.
• Output Configuration: The substitute must provide transistor output with base connection to preserve circuit topology compatibility.
• Current Transfer Ratio: Minimum CTR of 10% @ 10mA ensures consistent photodiode-to-transistor gain characteristics.
• Output Voltage and Current Ratings: Maximum output voltage of 30V and forward current of 60 mA define the load-driving capability.
• Switching Speed: Turn-on and turn-off times of 2µs establish the frequency response envelope.
• Package and Mounting: 6-SMD surface mount package with gull wing leads ensures mechanical and electrical compatibility with existing PCB layouts.
• Operating Temperature Range: The -55°C to 100°C range defines the thermal operating envelope.

The 4N28SR2VM qualifies as a substitute based on matching output topology, package configuration, and core electrical parameters. However, the isolation voltage rating differs: 4N28SR2VM provides 4170Vrms isolation versus the 4N28FR2VM's 7500Vpk specification.

Parameter Comparison

Engineering Selection Recommendations

The 4N28SR2VM is available as an active product with ROHS3 compliance, addressing supply chain continuity for the obsolete 4N28FR2VM. Both parts share identical output topology, package configuration, and core electrical characteristics including current transfer ratio, output voltage/current ratings, and switching speed.

The primary design consideration is isolation voltage rating. The 4N28FR2VM specifies 7500Vpk isolation, while the 4N28SR2VM provides 4170Vrms isolation. Selection of the 4N28SR2VM requires verification that the application's isolation voltage requirement does not exceed 4170Vrms. Applications requiring isolation voltage above this threshold cannot use the 4N28SR2VM as a direct substitute.

The 4N28SR2VM operates over a narrower temperature range (-40°C to 100°C) compared to the 4N28FR2VM (-55°C to 100°C). Applications requiring operation below -40°C must evaluate alternative solutions.

Frequently Asked Questions (FAQ)

Q: Can the 4N28SR2VM directly replace the 4N28FR2VM in all applications?

A: Direct substitution is possible only when the application's isolation voltage requirement does not exceed 4170Vrms. The 4N28FR2VM's 7500Vpk isolation rating is higher. Applications designed for the full 7500Vpk isolation capability require components meeting or exceeding this specification.

Q: What is the difference between Vpk and Vrms isolation ratings?

A: Vpk (peak voltage) and Vrms (RMS voltage) represent different measurement standards for isolation voltage. The 4N28FR2VM specifies 7500Vpk, while the 4N28SR2VM specifies 4170Vrms. These values reflect different testing methodologies and cannot be directly compared without conversion factors specific to the waveform and application context.

Q: Are the packages identical between these parts?

A: Both the 4N28FR2VM and 4N28SR2VM use 6-SMD surface mount packages with gull wing leads. PCB layout compatibility is maintained between these parts.

Q: What is the significance of the 4N28FR2VM being obsolete?

A: Obsolete status indicates the manufacturer has discontinued production. The 4N28SR2VM, classified as active, represents the current production alternative within the 4N28 optoisolator family.

Q: Does the 4N28SR2VM meet RoHS requirements?

A: The 4N28SR2VM is ROHS3 compliant. RoHS compliance status for the 4N28FR2VM is not specified in the available documentation.

Q: Are there temperature range limitations when substituting?

A: The 4N28SR2VM operates from -40°C to 100°C, while the 4N28FR2VM operates from -55°C to 100°C. Applications requiring operation below -40°C cannot use the 4N28SR2VM.