# SZMMSZ5226BT1G

**onsemi** · Zener Diodes · SOD-123

SZMMSZ5226BT1G 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 of the Zener diode, marked by the polarity band on the package; it is the reverse-regulation terminal, with the 500 mW rating on FR-5 board and a junction and storage range of -55 to +150 °C. |
| 2 | Anode | passive | Anode of the Zener diode; forward voltage is 0.95 V max at IF = 10 mA for the 5% series and 0.9 V max at IF = 10 mA for the 2% series per the electrical characteristics tables. |

## 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 | 3.14 | 3.3 | 3.47 | V | @ IZT = 20 mA; B (5%) suffix; TA = 25°C | 3 |
| Zener voltage tolerance (B suffix) |  | -5 |  | 5 | % | Standard tolerance on nominal Zener voltage (Note 3) | 3 |
| Maximum Zener Impedance | ZZT |  |  | 28 | Ω | @ IZT = 20 mA; IZ(AC) = 0.1 IZ(dc), f = 1 kHz | 3 |
| Maximum Zener Impedance | ZZK |  |  | 1600 | Ω | @ IZK = 0.25 mA; IZ(AC) = 0.1 IZ(dc), f = 1 kHz | 3 |
| Reverse Leakage Current | IR |  |  | 25 | A | @ VR = 1 V | 3 |
| Forward Voltage | VF |  |  | 0.9 | V | @ IF = 10 mA | 3 |
| Total Power Dissipation on FR-5 Board | PD |  |  | 500 | mW | On FR-5 board (Note 1) @ TL = 75°C | 1 |
| Derating above 75°C | PD |  |  | 6.7 | mW/°C | Derated above TL = 75°C | 1 |
| Thermal Resistance, Junction-to-Ambient | RJA |  |  | 340 | °C/W | Note 2 (infrared scan method) | 1 |
| Thermal Resistance, Junction-to-Lead | RJL |  |  | 150 | °C/W | Note 2 (infrared scan method) | 1 |
| Junction and Storage Temperature Range | TJ, Tstg | -55 |  | 150 | °C |  | 1 |

## CAD (KiCad official)

- Symbol: `SZMMSZ5226BT1G`
- Footprint: `Diode_SMD:D_SOD-123F`
- 3D model: SOD-123 (KiCad packages3D, STEP)
- 3D model files: `szmmsz5226bt1g-etched.step` / `szmmsz5226bt1g-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `szmmsz5226bt1g.step` / `szmmsz5226bt1g.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [onsemi datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590905804717436928) (8 pp, sha256 `2711e46b01090f07`, retrieved 2026-10-18, 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/szmmsz5226bt1g-datasheet.pdf)