# MM3Z18VB

**onsemi** · Zener Diodes · SOD-323FL

MM3Z18VB from onsemi, in a SOD-323FL. 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 | The band-marked terminal is the cathode per the connection diagram, and the datasheet states no further electrical limits for this pin. |
| 2 | A | passive | The terminal without the cathode band is the anode of the Zener diode, and the datasheet states no further electrical limits for this pin. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | onsemi |
| Package | SOD-323FL |
| Category | Diodes |
| 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 |
|---|---|---|---|---|---|---|---|
| Zener voltage | VZ | 17.64 | 18 | 18.36 | V | IZT = 5 mA; pulse test 10 ms | 2 |
| Zener voltage tolerance (B series, standard) |  | -2 |  | 2 | % | B series standard tolerance on nominal VZ | 2 |
| Zener impedance | ZZT |  |  | 42 | Ω | IZT = 5 mA | 2 |
| Zener impedance at knee | ZZK |  |  | 212 | Ω | IZK = 1 mA | 2 |
| Reverse leakage current | IR |  |  | 0.045 | A | VR = 12.6 V | 2 |
| Forward voltage | VF |  |  | 1 | V | IF = 10 mA | 1 |
| Power dissipation | PD |  |  | 200 | mW | TA = 25°C (table header) | 1 |
| Storage temperature range | TSTG | -65 |  | 150 | C |  | 1 |
| Maximum junction temperature | TJ |  |  | 150 | C |  | 1 |
| Thermal resistance, junction to ambient | RJA |  |  | 595 | C/W |  | 1 |

## CAD (KiCad official)

- Symbol: `MM3Z18VB`
- Footprint: `Diode_SMD:D_SOD-323F`
- 3D model: SOD-323FL (KiCad packages3D, STEP)
- 3D model files: `mm3z18vb-etched.step` / `mm3z18vb-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `mm3z18vb.step` / `mm3z18vb.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/8589985941374349312) (7 pp, sha256 `35648400ecaafb92`, retrieved 2026-10-16, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (text), consensus `claude-sonnet-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/mm3z18vb-datasheet.pdf)