Alternatives to onsemi 4N37
onsemi 4N37 and its qualified second sources, compared on form/fit/function, stock, lifecycle and price — the same checks Parter runs inside a BOM.
 4N37onsemi | 4N37Monsemi |  4N37Vishay Semiconductor Opto Division | +3more | |
|---|---|---|---|---|
| FFF Compatibility | Standard 6-DIP footprint and identical pin layout (Pin 1 Anode, Pin 2 Cathode, Pin 3 NC, Pin 4 Emitter, Pin 5 Collector, Pin 6 Base).Identical physical dimensions and mounting style (through-hole DIP-6), though housed in a white package body instead of the obsolete black body.Isolation voltage (4170Vrms) and maximum DC forward current (60mA) are lower than the original obsolete part's ratings (5300Vrms and 100mA respectively). | Standard 6-DIP footprint and identical pinout (Pin 1 Anode, Pin 2 Cathode, Pin 3 NC, Pin 4 Emitter, Pin 5 Collector, Pin 6 Base).Standard DIP-6 dimensions and through-hole mounting.Isolation voltage is slightly lower (5000Vrms vs 5300Vrms) and max forward current is reduced (50mA vs 100mA). | ||
 AI Summary | 4N37 by onsemi: Optoisolator Transistor with Base Output 5300Vrms 1 Channel 6-DIP. | The 4N37M is onsemi's active, direct white-package replacement for the obsolete black-packaged 4N37. It matches the original's primary characteristics, including a minimum Current Transfer Ratio (CTR) of 100% at 10mA, but has slightly lower absolute maximum limits.
| Vishay's 4N37 is a widely used and highly reliable second-source alternative. It operates with the same pin configuration and package, providing strong isolation performance up to 5000Vrms.
| |
| Lifecycle Status | Obsolete | Active | Active | |
| Market Availability | Discontinued | In stock | In stock | |
| REACH | REACH | REACH | REACH | |
| RoHS | RoHS | RoHS | RoHS | |
| Description | Optoisolator Transistor with Base Output 5300Vrms 1 Channel 6-DIP | Optoisolator Transistor with Base Output 4170Vrms 1 Channel 6-DIP | Optoisolator Transistor with Base Output 5000Vrms 1 Channel 6-DIP | |
| Manufacturer | onsemi | onsemi | Vishay Semiconductor Opto Division | |
| Type | Optocouplers, Optoisolators | Optocouplers, Optoisolators | Optocouplers, Optoisolators | |
| Datasheet | Open | Open | Open | |
| Lead Time | Unknown | 24 weeks | 18 weeks | |
| Country of Origin | - | - | - | |
| Export Control Class Number | EAR99 | EAR99 | EAR99 | |
| HTSUS Code | 8541.49.8000 | - | - | |
| Moisture Sensitivity Level | 1 (Unlimited) | - | - | |
| Input Type | DC | - | - | |
| Output Type | Transistor with Base | - | - | |
| Mounting Type | Through Hole | - | - | |
| Package / Case | 6-DIP (0.300", 7.62mm) | - | - | |
| Number of Channels | 1 | - | - | |
| Voltage - Isolation | 5300Vrms | - | - | |
| Vce Saturation (Max) | 300mV | - | - | |
| Operating Temperature | -55°C ~ 100°C | - | - |
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Related parts
| Part | Market availability | Lifecycle | Alternatives available |
|---|---|---|---|
 4N37Monsemi | In stock | Active | 3Alternatives availableSee Alternatives |
| 4N32SVMonsemi | Discontinued | Obsolete | 5Alternatives availableSee Alternatives |
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Frequently asked questions
Yes. The onsemi 4N37 is marked obsolete, so the manufacturer has discontinued it and any remaining supply is limited to distributor stock. The qualified second sources on this page are active parts you can design in today.
The closest qualified second sources for the onsemi 4N37 are the 4N37M (onsemi) and the 4N37 (Vishay Semiconductor Opto Division), out of 5 matched alternatives in total. Each is compared against the original on fit, form and function in the table above.
Not always. The alternatives to the 4N37 are matched on function but can differ in package, pinout or a key parameter, so review the fit/form/function notes in the table and the datasheet before designing one in.
The 4N37 (onsemi) is a part in the Optocouplers, Optoisolators category. This page lists qualified, cross-referenced replacements for it with a side-by-side comparison.
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