# BZX84C3V9A

**Shandong Jingdao Microelectronics** · Zener Diodes · SOT-23

BZX84C3V9A from Shandong Jingdao Microelectronics, 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 single zener diode (Suffix A), zener voltage 3.82V min to 3.98V max at IZT for the 3.9V grade. |
| 2 | NC | unconnected | No internal connection in the Suffix A single-diode configuration; the package drawing shows no diode connected to pin 2. |
| 3 | K | passive | Cathode of the single zener diode (Suffix A), which sits at the positive voltage in zener reverse operation; maximum power dissipation is 350mW. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Shandong Jingdao Microelectronics |
| 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 VZT (C3V9A, C-series ±5%) | VZT | 3.7 | 3.9 | 4.1 | V | IZT = 5 mA; VZT tested with pulses (20 ms) | 3 |
| Tolerance (C series) |  | -5 |  | 5 | % | C suffix in BZX84C3V9A = ±5% | 3 |
| Dynamic impedance ZZT max | ZZT |  |  | 130 | Ω | at IZT = 5 mA | 3 |
| Reverse current IR max | IR |  |  | 5 | μA | at VR = 1 V | 3 |
| Power dissipation (total) | Ptot |  |  | 350 | mW |  | 1 |
| Operating and storage temperature range | Tj, Tstg | -55 |  | 150 | °C |  | 1 |

## CAD (KiCad official)

- Symbol: `BZX84C3V9A`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `bzx84c3v9a-etched.step` / `bzx84c3v9a-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bzx84c3v9a.step` / `bzx84c3v9a.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Shandong Jingdao Microelectronics datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590892716421165056) (4 pp, sha256 `abb7c0e41de9a21a`, 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/bzx84c3v9a-datasheet.pdf)