# MM3Z5B1

**ST(Semtech)** · Zener Diodes · SOD-323

MM3Z5B1 from ST(Semtech), 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 | Cathode | passive | Cathode pin of the zener diode, identified on the SOD-323 package by the cathode line marking. |
| 2 | Anode | passive | Anode pin of the zener diode, shown as pin 2 in the SOD-323 top view and symbol. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | ST(Semtech) |
| 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 nominal | Vznom |  | 5.1 |  | V |  | 2 |
| Zener voltage tolerance |  | -2 |  | 2 | % | Zener Voltage Tolerance feature | 1 |
| Zener voltage range | VZT | 4.998 |  | 5.202 | V | at IZT 5 mA; VZT tested with pulses (20 ms) | 2 |
| Dynamic impedance | ZZT |  |  | 130 | Ω | at IZT 5 mA | 2 |
| Reverse leakage current | IR |  |  | 2 | μA | at VR 1 V 1.5 V | 2 |
| Forward voltage | VF |  |  | 0.9 | V | at IF = 10 mA | 1 |
| Total power dissipation | Ptot |  |  | 300 | mW | Ta = 25 OC | 1 |
| Junction temperature | Tj |  |  | 150 | ℃ |  | 1 |
| Storage temperature range | Tstg | -55 |  | 150 | ℃ |  | 1 |
| Thermal resistance junction to ambient air | RθJA |  |  | 417 | ℃/W | Junction to Ambient Air | 1 |

## CAD (KiCad official)

- Symbol: `MM3Z5B1`
- Footprint: `Diode_SMD:D_SOD-323`
- 3D model: SOD-323 (KiCad packages3D, STEP)
- 3D model files: `mm3z5b1-etched.step` / `mm3z5b1-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `mm3z5b1.step` / `mm3z5b1.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [ST(Semtech) datasheet](docs/mm3z5b1-datasheet.pdf) (4 pp, sha256 `5b9de85597be12a4`, retrieved 2026-10-27, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (text), consensus `off` (skipped (clean text read)), 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/mm3z5b1-datasheet.pdf)