# SMF5942A

**Changjing** · Zener Diodes · SOD-123FL

SMF5942A from Changjing, in a SOD-123FL. 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 banded/marked end per the datasheet; pad 1 of the KiCad diode footprint. |
| 2 | A | passive | Anode. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| Package | SOD-123FL |
| 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 (min / nominal AVE. / max) | VZ | 48.45 | 51 | 53.55 | V | @IZT 7.3 mA | 2 |
| Maximum zener impedance | ZZT |  |  | 70 | Ω | @IZT 7.3 mA | 2 |
| Maximum zener impedance | ZZK |  |  | 1100 | Ω | @IZK 0.25 mA | 2 |
| Maximum reverse leakage current | IR |  |  | 0.5 | µA | @VR 38.8 V | 2 |
| Maximum DC zener current | IZM |  |  | 18 | mA |  | 2 |
| Tolerance on nominal zener voltage (standard, suffix A) |  | -5 |  | 5 | % | Standard tolerance on nominal zener voltage, note (1) | 2 |
| Power dissipation | Pd |  |  | 1.5 | W | TL=75℃ | 1 |
| Operation junction and storage temperature range | TJ,Tstg | -55 |  | 150 | ℃ |  | 1 |
| Forward voltage | VF |  |  | 1.5 |  | =200mA | 1 |
| Thermal resistance, junction to ambient | RθJA |  |  | 170 | ℃/W | Between junction to ambient | 1 |
| Thermal resistance, junction to lead | RθJL |  |  | 25 | ℃/W | Between junction to lead | 1 |

## CAD (KiCad official)

- Symbol: `SMF5942A`
- Footprint: `Diode_SMD:D_SOD-123F`
- 3D model: SOD-123FL (KiCad packages3D, STEP)
- 3D model files: `smf5942a-etched.step` / `smf5942a-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `smf5942a.step` / `smf5942a.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Changjing datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590905947265187841) (5 pp, sha256 `687e0a4522a0b1ae`, retrieved 2026-10-15, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins`, primary `cathode-band convention` (convention), consensus `off` (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/smf5942a-datasheet.pdf)