# SMAJ45AJ

**WeEn Semiconductors** · ESD And Surge Protection (TVS/ESD) · SMA

SMAJ45AJ from WeEn Semiconductors, in a SMA. 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 | WeEn Semiconductors |
| Package | SMA |
| 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 | 50.4 |  | 54.9 | V | Tj = 25 °C; test current IT = 1 mA | 2 |
| Max. clamping voltage | VC |  |  | 72.7 | V | Tj = 25 °C; @ Ipp = 5.5 A | 2 |
| Maximum reverse leakage | IR |  |  | 1 | μA | Tj = 25 °C; @ VR = 45 V | 2 |
| Max. peak pulse current | Ipp |  |  | 5.5 | A |  | 2 |
| Peak pulse power | PPPM |  |  | 400 | W | footnote [1]: IEC 61643-321, 10/1000 μs current waveform | 1 |
| Steady state power dissipation | PM(AV) |  |  | 3.3 | W | on infinite heatsink at Ta = 50 °C | 1 |
| Peak forward surge current | IFSM |  |  | 60 | A | tp = 8.3 ms; single half sine-wave pulse; duty cycle = 4 pulses per minute maximum; unidirectional units only | 1 |
| Forward on-state voltage | VF |  |  | 3.5 | V | IF = 35 A; unidirectional units only | 1 |
| Storage temperature range | Tstg | -65 |  | 150 | °C |  | 1 |
| Operating temperature range | Tj | -65 |  | 150 | °C |  | 1 |

## CAD (KiCad official)

- Symbol: `SMAJ45AJ`
- Footprint: `Diode_SMD:D_SMA`
- 3D model: SMA (KiCad packages3D, STEP)
- 3D model files: `smaj45aj-etched.step` / `smaj45aj-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `smaj45aj.step` / `smaj45aj.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [WeEn Semiconductors datasheet](docs/smaj45aj-datasheet.pdf) (7 pp, sha256 `17c388c201e50792`, retrieved 2026-10-21, 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/smaj45aj-datasheet.pdf)