# BZX84C39Q

**Yangzhou Yangjie Elec Tech** · Zener Diodes · SOT-23

BZX84C39Q from Yangzhou Yangjie Elec Tech, in a SOT-23. 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 | A | passive | Anode of the Zener diode, shown on the page 1 schematic connected to the diode's anode side (VZ 37 V min, 39 V typ, 41 V max at IZT=2 mA for BZX84C39Q). |
| 2 | NC | unconnected | No internal connection; the page 1 schematic shows pin 2 with no connection to the diode. |
| 3 | K | passive | Cathode of the Zener diode, connected to the diode's cathode side; maximum power dissipation of the package is 350 mW. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Yangzhou Yangjie Elec Tech |
| Package | SOT-23 |
| Category | Diodes |
| Pins | 3 |

## 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) | Vz | 37 | 39 | 41 | V | Izt = 2 mA | 2 |
| Zener voltage tolerance |  | -5 |  | 5 | % |  | 1 |
| Zener impedance | Zzt |  |  | 130 | Ω | IZt = 2 mA | 2 |
| Zener impedance at knee | Zzk |  |  | 350 | Ω | Izk = 0.5 mA | 2 |
| Reverse leakage current | IR |  |  | 0.1 | uA | VR = 27.3 V | 2 |
| Typical temperature coefficient |  | 33.4 |  | 41.2 | mV/℃ | IZTC = 2 mA | 2 |
| Power dissipation | PD |  |  | 350 | mW | Ta=25℃ | 1 |
| Storage temperature range | Tstg | -55 |  | 150 | °C |  | 1 |
| Junction temperature | TJ | -55 |  | 150 | °C |  | 1 |
| Maximum forward voltage | VF |  |  | 0.9 | V | IF = 10 mAdc | 1 |
| Thermal resistance junction to ambient air | RθJA |  | 357 |  | °C/W |  | 1 |

## Materials and finish

As the datasheet states them (page.json `metadata.appearance`; the 3D model's colours follow it).

| Part | Material | Colour / plating | Datasheet says | Page |
|---|---|---|---|---|
| housing |  | black | 4. Body color: Black | 5 |
| contacts |  | tin | ● Terminals: Tin plated leads, solderable per J-STD-002 and JESD22-B102 | 1 |

## CAD (KiCad official)

- Symbol: `BZX84C39Q`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `bzx84c39q-etched.step` / `bzx84c39q-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bzx84c39q.step` / `bzx84c39q.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Yangzhou Yangjie Elec Tech datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8603581503649964032) (6 pp, sha256 `6ee6bf4524a8b88e`, retrieved 2026-10-18, 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/bzx84c39q-datasheet.pdf)