# SMF45A

**FOSAN** · ESD And Surge Protection (TVS/ESD) · SOD-123FL

SMF45A from FOSAN, in a SOD-123FL. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | K | passive | Cathode: the banded/marked end per the datasheet; pad 1 of the KiCad diode footprint. |
| 2 | A | passive | Anode. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | FOSAN |
| Package | SOD-123FL |
| Category | Circuit Protection |
| Pins | 2 |

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Breakdown voltage | VBR | 50 |  | 57.5 | V | IT = 1 mA | 2 |
| Clamping voltage | VC |  | 72.7 |  | V | at IPP = 2.75 A | 2 |
| Peak pulse current | IPP |  | 2.75 |  | A |  | 2 |
| Reverse leakage current | IR |  | 1 |  | µA | at VRWM = 45 V | 2 |
| Reverse stand-off working voltage | VRWM |  | 45 |  | V |  | 2 |
| Peak power dissipation | PPK |  |  | 200 | W |  | 1 |
| Junction/storage temperature | TJ,Tstg | -55 |  | 150 | ℃ |  | 1 |
| Thermal resistance junction-ambient | RθJA |  | 125 |  | ℃/W | junction-ambient | 1 |

## CAD (KiCad official)

- Symbol: `SMF45A`
- Footprint: `Diode_SMD:D_SOD-123F`
- 3D model: SOD-123FL (KiCad packages3D, STEP)
- 3D model files: `smf45a-etched.step` / `smf45a-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `smf45a.step` / `smf45a.glb` are the bare package body.

## Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

- **Datasheet:** [FOSAN datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8757317693513457664) (4 pp, sha256 `361a736b995ddeab`, retrieved 2026-10-26, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins`, primary `cathode-band convention` (convention), consensus `off` (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/smf45a-datasheet.pdf)