# 1SMB5951BT3G

**onsemi** · Zener Diodes · SMB

1SMB5951BT3G from onsemi, in a 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, marked by the polarity band; Zener voltage is 114 V min, 120 V nom and 126 V max at IZT = 3.1 mA for the 1SMB5951B. |
| 2 | A | passive | Anode; maximum steady-state power dissipation is 3.0 W at TL = 75°C and maximum DC Zener current IZM is 12 mA for the 1SMB5951B. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | onsemi |
| Package | SMB |
| Category | Diodes |
| Pins | 2 |

## CAD (KiCad official)

- Symbol: `1SMB5951BT3G`
- Footprint: `Diode_SMD:D_SMB`
- 3D model: SMB (KiCad packages3D, STEP)
- 3D model files: `1smb5951bt3g-etched.step` / `1smb5951bt3g-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `1smb5951bt3g.step` / `1smb5951bt3g.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [onsemi datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8588880043666128896) (6 pp, sha256 `e95f4deeabd8ea97`, retrieved 2026-10-13, 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/1smb5951bt3g-datasheet.pdf)