# MM5Z9V1ST1G

**onsemi** · Zener Diodes · SOD-523

MM5Z9V1ST1G from onsemi, 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 terminal, identified by the polarity band on the SOD-523 package; for the MM5Z9V1ST1G the Zener voltage VZ is 8.85 V min to 9.23 V max at IZT 5.0 mA. |
| 2 | Anode | passive | Anode terminal of the Zener diode (Style 1 pin assignment); the series forward voltage is 0.9 V max at IF 10 mA. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | onsemi |
| 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 |
|---|---|---|---|---|---|---|---|
| Reverse Zener Voltage @ IZT | VZ | 8.85 |  | 9.23 | V | @ IZT, Izt = 5.0 mA | 2 |
| Maximum Zener Impedance @ IZK | ZZK |  |  | 160 |  | IZ = 1.0 mA | 2 |
| Maximum Zener Impedance @ IZT | ZZT |  |  | 15 |  | IZ = IZT @ 10% Mod | 2 |
| Reverse Leakage Current @ VR | IR |  |  | 0.5 | µA | @ VR = 6.0 V | 2 |
| Maximum Temperature Coefficient of VZ | dVZ/dt | 3.8 |  | 7 | mV/k | @ IZT1 = 5 mA | 2 |
| Max. Capacitance | C |  |  | 130 | pF | @ VR = 0 and f = 1 MHz | 2 |
| Forward Voltage | VF |  |  | 0.9 | V | @ IF = 10 mA | 2 |
| Total Device Dissipation FR-4 Board | PD |  |  | 500 | mW | @ TA = 25°C (Note 1) | 1 |
| Derate above 25°C |  |  |  | 4 | mW/°C | Derate above 25°C (Note 1) | 1 |
| Thermal Resistance from Junction-to-Ambient | RJA |  |  | 250 | °C/W | (Note 1) FR-4 board, 1 cm² mounting pad | 1 |
| Operating Junction and Storage Temperature Range | TJ, Tstg | -65 |  | 150 | °C |  | 1 |

## CAD (KiCad official)

- Symbol: `MM5Z9V1ST1G`
- Footprint: `Diode_SMD:D_SOD-523`
- 3D model: SOD-523 (KiCad packages3D, STEP)
- 3D model files: `mm5z9v1st1g-etched.step` / `mm5z9v1st1g-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `mm5z9v1st1g.step` / `mm5z9v1st1g.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/8589981681484017664) (5 pp, sha256 `6752ee2f7ea93ddc`, retrieved 2026-10-14, 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/mm5z9v1st1g-datasheet.pdf)