# AD-BZT52B18S

**Changjing** · Zener Diodes · SOD-323

AD-BZT52B18S from Changjing, 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 | 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-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 | VZ | 17.64 | 18 | 18.36 | V | @ IZT = 5mA | 2 |
| Maximum Zener impedance | ZZT |  |  | 45 | Ω | @ IZT = 5mA, f = 1kHz | 2 |
| Maximum Zener impedance (knee) | ZZK |  |  | 225 | Ω | @ IZK = 1.0mA, f = 1kHz | 2 |
| Maximum reverse current | IR |  |  | 0.1 | µA | VR = 12.6V | 2 |
| Temperature coefficient of Zener voltage |  | 12.4 |  | 16 | mV/°C | @ IZTC = 5mA | 2 |
| Forward voltage | VF |  |  | 0.9 | V | IF = 10mA, Tj = 25°C | 1 |
| Power dissipation | PD |  |  | 200 | mW | Tj = 25°C, mounted on ceramic PCB | 1 |
| Thermal resistance from junction to ambient | RθJA |  | 625 |  | °C/W | mounted on ceramic PCB 7.6mm x 9.4mm x 0.87mm, pad area 25mm2 | 1 |
| Operating junction and storage temperature range | Tj, Tstg | -55 |  | 150 | °C |  | 1 |

## CAD (KiCad official)

- Symbol: `AD-BZT52B18S`
- Footprint: `Diode_SMD:D_SOD-323`
- 3D model: SOD-323 (KiCad packages3D, STEP)
- 3D model files: `ad-bzt52b18s-etched.step` / `ad-bzt52b18s-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ad-bzt52b18s.step` / `ad-bzt52b18s.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/8603182079673331712) (6 pp, sha256 `e4e08709786b492a`, retrieved 2026-10-22, 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/ad-bzt52b18s-datasheet.pdf)