# BZX8850S-C3V9-QYL

**Nexperia** · Zener Diodes · SOD-882

BZX8850S-C3V9-QYL from Nexperia, in a SOD-882. 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 of the voltage regulator diode (marking bar indicates the cathode); VZ for the C3V9 type is 3.70 V to 4.10 V at IZ = 50 µA. |
| 2 | A | passive | Anode of the voltage regulator diode; forward voltage is max 0.9 V at IF = 10 mA and IF is limited to 200 mA. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Nexperia |
| Package | SOD-882 |
| 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 |
|---|---|---|---|---|---|---|---|
| Working voltage | VZ | 3.7 |  | 4.1 | V | IZ = 50 µA, Tj = 25 °C | 4 |
| Differential resistance | rdiff |  |  | 600 | Ω | IZ = 50 µA, Tj = 25 °C | 4 |
| Differential resistance | rdiff |  |  | 95 | Ω | IZ = 1 mA, Tj = 25 °C | 4 |
| Differential resistance | rdiff |  |  | 5 | Ω | IZ = 5 mA, Tj = 25 °C | 4 |
| Temperature coefficient | SZ | -2.7 |  | 2.5 | mV/K | IZ = 5 mA, Tj = 25 °C | 4 |
| Reverse current | IR |  |  | 2 | µA | Tj = 25 °C; VR = 2.0 V | 4 |
| Diode capacitance | Cd |  |  | 150 | pF | f = 1 MHz; VR = 0 V | 4 |
| Forward voltage | VF |  |  | 0.9 | V | IF = 10 mA; pulse test tp ≤ 300 μs; δ ≤ 0.02 | 4 |
| Forward current | IF |  |  | 200 | mA |  | 3 |
| Non-repetitive peak reverse power dissipation | PZSM |  |  | 40 | W | tp = 100 µs; square wave; Tj = 25 °C; prior to surge | 3 |
| Total power dissipation | Ptot |  |  | 365 | mW | Tamb ≤ 25 °C | 3 |
| Junction temperature | Tj |  |  | 150 | °C |  | 3 |
| Ambient temperature | Tamb | -55 |  | 150 | °C |  | 3 |
| Storage temperature | Tstg | -65 |  | 150 | °C |  | 3 |
| Thermal resistance from junction to ambient | Rth(j-a) |  |  | 340 | K/W | in free air | 3 |

## CAD (KiCad official)

- Symbol: `BZX8850S-C3V9-QYL`
- Footprint: `Diode_SMD:D_SOD-882`
- 3D model: SOD-882 (KiCad packages3D, STEP)
- 3D model files: `bzx8850s-c3v9-qyl-etched.step` / `bzx8850s-c3v9-qyl-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bzx8850s-c3v9-qyl.step` / `bzx8850s-c3v9-qyl.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Nexperia datasheet](https://assets.nexperia.com/documents/data-sheet/BZX8850S-C3V9-QYL.pdf) (11 pp, sha256 `89cb2b56ec72d003`, retrieved 2026-10-23, tier: manufacturer)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (text), consensus `claude-sonnet-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/bzx8850s-c3v9-qyl-datasheet.pdf)