# ZMM20B

**MSKSEMI** · Zener Diodes · LL-34

ZMM20B from MSKSEMI, in a LL-34. 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 of the glass MiniMELF body marked with the cathode band; for the ZMM20B Zener (VZ 19.6 to 20.4 V at IZT = 5 mA) this terminal goes to the positive side in reverse breakdown. |
| 2 | A | passive | Anode, the end opposite the cathode mark; it is the negative-side terminal of the Zener, and the datasheet gives Ptot of 500 mW and Tj of 175 °C for the part. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | MSKSEMI |
| Package | LL-34 |
| Category | Diodes |
| Pins | 2 |

## CAD (KiCad official)

- Symbol: `ZMM20B`
- Footprint: `Diode_SMD:D_MiniMELF`
- 3D model: LL-34 (KiCad packages3D, STEP)

## Provenance

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

- **Datasheet:** [MSKSEMI datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8603119773471555584) (4 pp, sha256 `1bfe640430f80bfb`, 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/zmm20b-datasheet.pdf)