# SMBJ400A

**YFW** · ESD And Surge Protection (TVS/ESD) · DO-214AA(SMB)

SMBJ400A from YFW, in a DO-214AA(SMB). 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 | Cathode | passive | Cathode terminal of the unipolar SMBJ400A (no CA suffix); for this part the datasheet gives reverse stand-off voltage VR = 400 V, breakdown VBR 447.00 V min to 494.00 V max at IT = 1 mA, and maximum clamping voltage VC 648 V at IPP 0.9 A. |
| 2 | Anode | passive | Anode terminal of the unipolar SMBJ400A (no CA suffix), which carries the surge current with the cathode; the datasheet rates the part for peak pulse power of 600 W (10/1000 µs waveform) and operating junction and storage temperature of -65 to +150 °C. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | YFW |
| Package | DO-214AA(SMB) |
| Category | Circuit Protection |
| Pins | 2 |

## CAD (KiCad official)

- Symbol: `SMBJ400A`
- Footprint: `Diode_SMD:D_SMB`
- 3D model: DO-214AA(SMB) (KiCad packages3D, STEP)
- 3D model files: `smbj400a-etched.step` / `smbj400a-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `smbj400a.step` / `smbj400a.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [YFW datasheet](docs/smbj400a-datasheet.pdf) (4 pp, sha256 `15c4cd6b3a64c6dc`, retrieved 2026-10-22, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (vision), consensus `claude-opus-5-5` (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/smbj400a-datasheet.pdf)