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onsemi 4N25TM — Optoisolators

onsemi 4N25TM Optoisolator, 7500Vpk, 6-DIP, Obsolete

MPN4N25TM
Obsolete

onsemi 4N25TM Optoisolator, DC input, Transistor with Base output, 1 Channel, 6-DIP (0.400", 10.16mm), Through Hole, 7500Vpk isolation, 20% CTR min at 10mA.

$0.2060Ref. price · indicative, final on quote
onsemi 4N25TM datasheet (PDF)
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

4N25TM specifications
ParameterValue
Input typeDC
Output typeTransistor with Base
MountingThrough Hole
Voltage - isolation7500Vpk
Voltage - output30V
Voltage - forward (Vf)1.18V
Current transfer ratio20% @ 10mA
Current - DC forward (If)60 mA
Operating temperature-40°C ~ 100°C
PackageTube
Case6-DIP (0.400\", 10.16mm)
Channels1
Vce saturation500mV
Turn on (Turn off time)2µs, 2µs

Product details

7500Vpk isolation in a 6-DIP through-hole package

The onsemi 4N25TM is a single-channel optoisolator in a 6-DIP (0.400", 10.16mm) through-hole package, delivering 7500Vpk of galvanic isolation between a DC input LED and a transistor output with base access. Its 20% minimum current transfer ratio at 10 mA forward current ensures reliable DC-level coupling across the isolation barrier, while the 2 µs typical turn-on and turn-off times suit moderate-speed switching in industrial controls and power supply feedback loops.

No pin-compatible drop-in replacement is guaranteed from the original manufacturer; a board-level requalification may be needed if migrating to a different optoisolator.

Parametric fit for legacy DIP-based designs

The 6-DIP (0.400", 10.16mm) lead spacing matches the industry-standard footprint used in through-hole optoisolator sockets and PCB layouts — no adapter or board spin is required for existing DIP-6 patterns.

Frequently asked questions

Where can I buy the 4N25TM and how is it quoted?

The 4N25TM is available through independent distribution.

What is the closest pin-compatible alternative to the 4N25TM?

No official pin-compatible successor is listed by onsemi. Functional equivalents from other manufacturers (e.g., Vishay, Broadcom) exist in the same 6-DIP footprint, but each has its own CTR and isolation ratings — verify the replacement against your application's minimum isolation voltage and CTR requirements.