3N261 Optoisolator Equivalent & Substitute Parts

Part Overview

The 3N261 is a through-hole optoisolator with transistor output, rated for 1000VDC isolation voltage and designed for single-channel DC input applications. This component features a TO-72-4 metal can package and is classified as obsolete. Due to its obsolete status and limited remaining inventory, identifying active equivalent parts is essential for ongoing design support and production continuity.

Substiute Parts

3N261

TT Electronics/Optek TechnologyIn Stock: 7813N261 Datasheet

Current PartRFQ

3N262

TT Electronics/Optek TechnologyIn Stock: 7033N262 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 3N261 is determined by the following critical parameters:

• Isolation Voltage: 1000VDC minimum
• Number of Channels: 1 channel
• Output Type: Transistor output
• Package Type: TO-72-4 metal can (through-hole)
• Input Type: DC
• Maximum Output Voltage: 30V
• Maximum Output Current: 30mA per channel
• Operating Temperature Range: -55°C ~ 125°C

The 3N262 qualifies as a direct substitute based on matching all critical electrical and mechanical parameters. Both parts share identical isolation voltage, channel configuration, output specifications, and package format. The primary distinction is product status and compliance certification.

Parameter Comparison

Engineering Selection Recommendations

The 3N262 is the direct substitute for the 3N261. Both components are manufactured by TT Electronics/Optek Technology and share identical electrical and mechanical specifications within the critical parameters that define functional equivalence.

The 3N262 offers the following advantages:

• Active Product Status: Currently in production and supported by the manufacturer
• Regulatory Compliance: ROHS3 compliant, whereas the 3N261 is non-compliant
• Improved Current Transfer Ratio Specification: The 3N262 provides a defined maximum CTR of 50% @ 1mA, compared to the 3N261's unspecified maximum, offering better performance predictability
• Inventory Availability: 684 units in stock versus 736 units of the obsolete 3N261

For new designs or production continuation, the 3N262 is the appropriate selection. For legacy systems currently using the 3N261, the 3N262 provides direct functional replacement without circuit modification.

Frequently Asked Questions (FAQ)

Q: Can the 3N262 directly replace the 3N261 in existing circuits?

A: Yes. Both parts share identical isolation voltage (1000VDC), output voltage rating (30V maximum), output current rating (30mA), and package format (TO-72-4 metal can). No circuit modifications are required.

Q: What is the difference in Current Transfer Ratio between these parts?

A: The 3N261 specifies a minimum CTR of 5% @ 1mA with no maximum defined. The 3N262 specifies a minimum CTR of 10% @ 1mA and a maximum of 50% @ 1mA. The 3N262's defined range provides tighter performance specification. Circuits designed for the 3N261's 5% minimum will operate within the 3N262's specification range.

Q: Why is the 3N261 listed as obsolete?

A: The 3N261 has been discontinued by the manufacturer. The 3N262 is the active equivalent part and is the recommended selection for all new applications.

Q: Are there any compliance differences between these parts?

A: Yes. The 3N262 is ROHS3 compliant, while the 3N261 is RoHS non-compliant. Both are REACH Unaffected and classified as EAR99 for export control purposes.

Q: Is the TO-72-4 package still in production?

A: The 3N262 is available in TO-72-4 metal can packaging and is currently in production. This package format remains supported by TT Electronics/Optek Technology.

Q: What is the operating temperature range for both parts?

A: Both the 3N261 and 3N262 operate across -55°C to 125°C, providing identical thermal performance specifications.