# MM5Z3V9B

**ST Semtech** · Zener Diodes · SOD-523

MM5Z3V9B from ST Semtech, in a SOD-523. 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 | Cathode | passive | Cathode of the planar Zener diode; the cathode is identified by the cathode line in the SOD-523 marking. |
| 2 | Anode | passive | Anode of the planar Zener diode in the 2-lead SOD-523 surface-mount package. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | ST Semtech |
| Package | SOD-523 |
| 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 |
|---|---|---|---|---|---|---|---|
| Power Dissipation | Ptot |  |  | 200 | mW | Absolute Maximum Ratings, Ta = 25 OC | 1 |
| Junction Temperature | Tj |  |  | 150 | ℃ | Absolute Maximum Ratings, Ta = 25 OC | 1 |
| Storage Temperature Range | TStg | -55 |  | 150 | ℃ | Absolute Maximum Ratings, Ta = 25 OC | 1 |
| Thermal Resistance Junction to Ambient Air | RthA |  |  | 635 | ℃/W |  | 1 |
| Forward Voltage | VF |  |  | 0.9 | V | at IF = 10 mA | 1 |
| Zener Voltage Range (MM5Z3V9B) | VZT | 3.89 |  | 4.16 | V | at lZT = 5 mA; VZ tested with pulses (20 ms) | 2 |
| Dynamic Impedance (MM5Z3V9B) | ZZT |  |  | 100 | Ω | at lZT = 5 mA; measured with very small AC current signal | 2 |
| Reverse Leakage Current (MM5Z3V9B) | IR |  |  | 5 | μA | at VR = 1 V | 2 |

## CAD (KiCad official)

- Symbol: `MM5Z3V9B`
- Footprint: `Diode_SMD:D_SOD-523`
- 3D model: SOD-523 (KiCad packages3D, STEP)
- 3D model files: `mm5z3v9b-etched.step` / `mm5z3v9b-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `mm5z3v9b.step` / `mm5z3v9b.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [ST Semtech datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8603065777914597376) (3 pp, sha256 `5acd252c61e6c21f`, retrieved 2026-10-15, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-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/mm5z3v9b-datasheet.pdf)