# MMSZ5231B

**hongjiacheng** · Zener Diodes · SOD-123

MMSZ5231B from hongjiacheng, in a SOD-123. 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, the end marked by the cathode line on the package; Zener voltage VZ is 4.85 V min / 5.1 V nom / 5.36 V max at IZT=20 mA for the MMSZ5231B. |
| 2 | A | passive | Anode, the end opposite the cathode line; maximum power dissipation is 500 mW and forward voltage is 0.9 V at IF=10 mA. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | hongjiacheng |
| Package | SOD-123 |
| Category | Diodes |
| Pins | 2 |

## CAD (KiCad official)

- Symbol: `MMSZ5231B`
- Footprint: `Diode_SMD:D_SOD-123F`
- 3D model: SOD-123 (KiCad packages3D, STEP)
- 3D model files: `mmsz5231b-etched.step` / `mmsz5231b-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `mmsz5231b.step` / `mmsz5231b.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [hongjiacheng datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8755883319731478528) (5 pp, sha256 `8894d63b414fbe83`, retrieved 2026-10-09, 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/mmsz5231b-datasheet.pdf)