# MM3Z51BW

**Shandong Jingdao Microelectronics** · Zener Diodes · SOD-323

MM3Z51BW from Shandong Jingdao Microelectronics, in a SOD-323. 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 zener diode; the datasheet gives no separate pin-level limit, and the device is rated at Ptot 300 mW with Tj/Tstg of -55 to +150 °C. |
| 2 | Anode | passive | Anode terminal of the zener diode; the datasheet gives no separate pin-level limit, and the device is rated at Ptot 300 mW with Tj/Tstg of -55 to +150 °C. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Shandong Jingdao Microelectronics |
| Package | SOD-323 |
| 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 (MM3Z51) | VZT | 48 | 51 | 54 | V | at IZT; VZT tested with pulses (20 ms) | 2 |
| Total power dissipation | Ptot |  |  | 300 | mW | Ta = 25 °C | 1 |
| Operating and storage temperature range | Tj, Tstg | -55 |  | 150 | °C |  | 1 |
| Typical thermal resistance junction to ambient | RθJA |  | 417 |  | °C/W | Junction to ambient at P.C.B. mounted with 2.0" X 2.0" (5 X 5 cm) copper areas pads | 1 |

## CAD (KiCad official)

- Symbol: `MM3Z51BW`
- Footprint: `Diode_SMD:D_SOD-323`
- 3D model: SOD-323 (KiCad packages3D, STEP)
- 3D model files: `mm3z51bw-etched.step` / `mm3z51bw-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `mm3z51bw.step` / `mm3z51bw.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Shandong Jingdao Microelectronics datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590184331999145984) (3 pp, sha256 `fc26b65eea5b0e47`, retrieved 2026-10-22, 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/mm3z51bw-datasheet.pdf)