component
MM1Z5254B
Public Made by Adomby adom
ST Semtech Zener Diodes, SOD-123. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
3D Model
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Symbol & Footprint
Schematic Symbol
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PCB Footprint
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Datasheet
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README
markdownMM1Z5254B
ST Semtech · Zener Diodes · SOD-123
MM1Z5254B from ST Semtech, 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 cathode line in the marking ("III" = Cathode line). |
| 2 | Anode | passive | Anode terminal of the Zener diode, opposite the cathode. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | ST Semtech |
| 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 (VZT) | VZT | 25.65 | 28.35 | V | IZT = 4.6 mA; pulsed 20 ms (note 1) | 2 | |
| Zener voltage tolerance | -5 | 5 | % | Printed as approximately ±5% (suffix B) | 1 | ||
| Dynamic impedance (ZZT) | ZZT | 41 | Ω | IZT = 4.6 mA; AC 1 kHz, IZ(AC) = 0.1 IZ(DC) (note 2) | 2 | ||
| Dynamic impedance at knee (ZZK) | ZZK | 600 | Ω | IZK = 0.25 mA; AC 1 kHz, IZ(AC) = 0.1 IZ(DC) (note 2) | 2 | ||
| Reverse current | IR | 0.1 | µA | VR = 21 V | 2 | ||
| Power dissipation | Ptot | 500 | mW | TL = 75℃ (note 1) | 1 | ||
| Operating junction temperature range | Tj | -55 | 150 | ℃ | 1 | ||
| Storage temperature range | Tstg | -55 | 150 | ℃ | 1 | ||
| Thermal resistance junction to ambient | RθJA | 340 | ℃/W | Mounted on FR-4 PCB 38×38×1.6 mm, single-sided Cu pad 25 mm² (note 2) | 1 | ||
| Thermal resistance junction to lead | RθJL | 150 | ℃/W | FR-4 PCB 89×38 mm (note 1) | 1 | ||
| Nominal Zener voltage | Vznom | 27 | V | 2 |
CAD (KiCad official)
- Symbol:
MM1Z5254B - Footprint:
Diode_SMD:D_SOD-123F - 3D model: SOD-123 (KiCad packages3D, STEP)
- 3D model files:
mm1z5254b-etched.step/mm1z5254b-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);mm1z5254b.step/mm1z5254b.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: ST Semtech datasheet (4 pp, sha256
34ce15c3c8c6df9b, retrieved 2026-10-17, tier: lcsc) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-haiku-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).