component
MMSZ5258BT3G
Public Made by Adomby adom
onsemi Zener Diodes, SOD-123. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
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MMSZ5258BT3G
onsemi · Zener Diodes · SOD-123
MMSZ5258BT3G 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; the Zener voltage for the MMSZ5258B is 36 V nominal (34.20 V to 37.80 V) at IZT = 3.4 mA. |
| 2 | Anode | passive | Anode of the Zener diode; the device is rated at 500 mW on an FR-4 or FR-5 board. |
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 |
|---|---|---|---|---|---|---|---|
| Zener Voltage | VZ | 34.2 | 36 | 37.8 | V | @ IZT = 3.4 mA, TA = 25°C | 4 |
| Zener Test Current | IZT | 3.4 | mA | Zener voltage test current | 4 | ||
| Maximum Zener Impedance | ZZT | 70 | Ω | @ IZT = 3.4 mA | 4 | ||
| Maximum Zener Impedance (knee) | ZZK | 700 | Ω | @ IZK = 0.25 mA | 4 | ||
| Reverse Leakage Current | IR | 0.1 | µA | @ VR = 27 V | 4 | ||
| Forward Voltage | VF | 0.9 | V | IF = 10 mA | 4 | ||
| Zener Voltage Tolerance | -5 | 5 | % | B suffix, on nominal Zener voltage | 4 | ||
| Total Power Dissipation on FR-5 Board | PD | 500 | mW | TL = 75°C | 2 | ||
| Power Derating above 75°C | PD | 6.7 | mW/°C | Derated above 75°C | 2 | ||
| Junction and Storage Temperature Range | TJ, Tstg | -55 | 150 | °C | 2 | ||
| Thermal Resistance, Junction-to-Ambient | RθJA | 340 | °C/W | Note 2 | 2 | ||
| Thermal Resistance, Junction-to-Lead | RθJL | 150 | °C/W | Note 2 | 2 | ||
| Maximum Case Temperature for Soldering | 260 | °C | 10 seconds | 2 |
CAD (KiCad official)
- Symbol:
MMSZ5258BT3G - Footprint:
Diode_SMD:D_SOD-123F - 3D model: SOD-123 (KiCad packages3D, STEP)
- 3D model files:
mmsz5258bt3g-etched.step/mmsz5258bt3g-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);mmsz5258bt3g.step/mmsz5258bt3g.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: onsemi datasheet (9 pp, sha256
d0ec390f70af561f, retrieved 2026-10-22, tier: manufacturer) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-sonnet-5-5(text), consensusclaude-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).
# MMSZ5258BT3G
**onsemi** · Zener Diodes · SOD-123
MMSZ5258BT3G 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; the Zener voltage for the MMSZ5258B is 36 V nominal (34.20 V to 37.80 V) at IZT = 3.4 mA. |
| 2 | Anode | passive | Anode of the Zener diode; the device is rated at 500 mW on an FR-4 or FR-5 board. |
## 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 |
|---|---|---|---|---|---|---|---|
| Zener Voltage | VZ | 34.2 | 36 | 37.8 | V | @ IZT = 3.4 mA, TA = 25°C | 4 |
| Zener Test Current | IZT | | 3.4 | | mA | Zener voltage test current | 4 |
| Maximum Zener Impedance | ZZT | | | 70 | Ω | @ IZT = 3.4 mA | 4 |
| Maximum Zener Impedance (knee) | ZZK | | | 700 | Ω | @ IZK = 0.25 mA | 4 |
| Reverse Leakage Current | IR | | | 0.1 | µA | @ VR = 27 V | 4 |
| Forward Voltage | VF | | | 0.9 | V | IF = 10 mA | 4 |
| Zener Voltage Tolerance | | -5 | | 5 | % | B suffix, on nominal Zener voltage | 4 |
| Total Power Dissipation on FR-5 Board | PD | | | 500 | mW | TL = 75°C | 2 |
| Power Derating above 75°C | PD | | | 6.7 | mW/°C | Derated above 75°C | 2 |
| Junction and Storage Temperature Range | TJ, Tstg | -55 | | 150 | °C | | 2 |
| Thermal Resistance, Junction-to-Ambient | RθJA | | | 340 | °C/W | Note 2 | 2 |
| Thermal Resistance, Junction-to-Lead | RθJL | | | 150 | °C/W | Note 2 | 2 |
| Maximum Case Temperature for Soldering | | | | 260 | °C | 10 seconds | 2 |
## CAD (KiCad official)
- Symbol: `MMSZ5258BT3G`
- Footprint: `Diode_SMD:D_SOD-123F`
- 3D model: SOD-123 (KiCad packages3D, STEP)
- 3D model files: `mmsz5258bt3g-etched.step` / `mmsz5258bt3g-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `mmsz5258bt3g.step` / `mmsz5258bt3g.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/mmsz5258bt3-d.pdf) (9 pp, sha256 `d0ec390f70af561f`, retrieved 2026-10-22, tier: manufacturer)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-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/mmsz5258bt3g-datasheet.pdf)