# MMSZ5272BT3G

**onsemi** · Zener Diodes · SOD-123

MMSZ5272BT3G from onsemi, in a SOD-123. 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 terminal of the Zener diode, identified on the package by the polarity band. |
| 2 | Anode | passive | Anode terminal of the Zener diode, the opposite terminal to the cathode. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | onsemi |
| Package | SOD-123 |
| 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 |
|---|---|---|---|---|---|---|---|
| Reverse Zener Voltage | VZ | 104.5 | 110 | 115.5 | V | @ IZT = 1.1 mA; TA = 25°C | 3 |
| Maximum Zener Impedance | ZZT |  |  | 750 | Ω | @ IZT = 1.1 mA | 3 |
| Maximum Zener Impedance | ZZK |  |  | 3000 | Ω | @ IZK = 0.25 mA | 3 |
| Reverse Leakage Current | IR |  |  | 0.1 | µA | @ VR = 84 V | 3 |
| Zener voltage tolerance (B suffix, ±5%) |  | -5 |  | 5 | % | B suffix standard tolerance on nominal Zener voltage | 3 |
| Total Power Dissipation on FR-5 Board | PD |  |  | 500 | mW | FR-5 board (Note 1) @ TL = 75°C | 1 |
| Thermal Resistance, Junction-to-Ambient | RJA |  |  | 340 | °C/W | Note 2 | 1 |
| Thermal Resistance, Junction-to-Lead | RJL |  |  | 150 | °C/W | Note 2 | 1 |
| Junction and Storage Temperature Range | TJ, Tstg | -55 |  | 150 | °C |  | 1 |
| Power Derating | PD |  | 6.7 |  | mW/°C | Derated above TL = 75°C (FR-5 board) | 1 |

## CAD (KiCad official)

- Symbol: `MMSZ5272BT3G`
- Footprint: `Diode_SMD:D_SOD-123F`
- 3D model: SOD-123 (KiCad packages3D, STEP)
- 3D model files: `mmsz5272bt3g-etched.step` / `mmsz5272bt3g-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `mmsz5272bt3g.step` / `mmsz5272bt3g.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [onsemi datasheet](https://www.onsemi.com/pdf/datasheet/mmsz5272bt3-d.pdf) (8 pp, sha256 `2711e46b01090f07`, retrieved 2026-10-30, tier: manufacturer)
- **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/mmsz5272bt3g-datasheet.pdf)