Alternatives to Littelfuse 1SMB51AT3G
Littelfuse 1SMB51AT3G and its qualified second sources, compared on form/fit/function, stock, lifecycle and price — the same checks Parter runs inside a BOM.
Equivalent and substitute parts for Littelfuse 1SMB51AT3G
 1SMB51AT3GLittelfuse | SZ1SMB51AT3GLittelfuse Inc. |  SMBJ51ALittelfuse Inc. | +4more | |
|---|---|---|---|---|
| FFF Compatibility | The part uses the identical DO-214AA (SMB) package with the same 2-pin unidirectional polarity (Cathode band marking).The package dimensions and footprint are identical to the original part.All critical electrical parameters such as 51V standoff voltage, 56.7V minimum breakdown, 82.4V clamping, and 600W peak power are identical. | The part uses the same DO-214AA (SMB) package and unidirectional 2-pin layout.The package and mounting footprint are physically identical.All critical specs match the original, including the 51V standoff and 600W peak power rating. | ||
 AI Summary | 1SMB51AT3G by Littelfuse: 82.4V Clamp 7.3A Ipp Tvs Diode Surface Mount SMB. | This is the active, AEC-Q101 automotive-qualified direct successor of the obsolete 1SMB51AT3G from Littelfuse. It offers identical electrical parameters, physical footprint, and pinout, making it the highest-confidence drop-in replacement.
| This is the standard commercial-grade drop-in equivalent from Littelfuse's popular SMBJ series. It perfectly matches the physical and electrical specifications of the original obsolete part.
| |
| Lifecycle Status | Obsolete | Active | Active | |
| Market Availability | Discontinued | In stock | In stock | |
| REACH | REACH | REACH | REACH | |
| RoHS | RoHS | RoHS | RoHS | |
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Related parts
| Part | Market availability | Lifecycle | Alternatives available |
|---|---|---|---|
 1SMB5.0AT3Gonsemi | Discontinued | Obsolete | 6Alternatives availableSee Alternatives |
 1SMB6.5AT3GLittelfuse | Discontinued | Obsolete | 6Alternatives availableSee Alternatives |
 1SMB58CAT3GLittelfuse | Discontinued | Obsolete | 6Alternatives availableSee Alternatives |
| 1SMB18CAT3GLittelfuse | Discontinued | Obsolete | 7Alternatives availableSee Alternatives |
| 1SMB18CAT3onsemi | Discontinued | Obsolete | 7Alternatives availableSee Alternatives |
 1SMC5.0AT3GLittelfuse | Discontinued | Obsolete | 7Alternatives availableSee Alternatives |
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Frequently asked questions
Yes. The Littelfuse 1SMB51AT3G 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 Littelfuse 1SMB51AT3G are the SZ1SMB51AT3G (Littelfuse Inc.) and the SMBJ51A (Littelfuse Inc.), out of 6 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 1SMB51AT3G 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 1SMB51AT3G (Littelfuse) is a part in the Transient Voltage Suppressors (TVS) category. This page lists qualified, cross-referenced replacements for it with a side-by-side comparison.
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