# SMBJ33A

**MDD Microdiode Semiconductor** · ESD And Surge Protection (TVS/ESD) · DO-214AA(SMB)

SMBJ33A from MDD Microdiode Semiconductor, 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 | K | passive | Cathode terminal, marked by the cathode band on the body for unidirectional SMBJ33A; stand-off voltage VRWM 33.0 V, breakdown 36.70~40.60 V at 1 mA, max clamping 53.3 V at 58... see review |
| 2 | A | passive | Anode terminal of the unidirectional TVS diode, the end opposite the cathode band, with 600 W peak pulse power at 10/1000μs. |

## Key specifications

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

## CAD (KiCad official)

- Symbol: `SMBJ33A`
- Footprint: `Diode_SMD:D_SMB`
- 3D model: DO-214AA(SMB) (KiCad packages3D, STEP)
- 3D model files: `smbj33a-etched.step` / `smbj33a-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `smbj33a.step` / `smbj33a.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [MDD Microdiode Semiconductor datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8757912085261373440) (5 pp, sha256 `95385273b5009dc9`, retrieved 2026-10-12, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (text+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/smbj33a-datasheet.pdf)