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MMSZ5251B
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Slkor SLKORMICRO Elec Zener Diodes, SOD-123. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
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MMSZ5251B
Slkor SLKORMICRO Elec · Zener Diodes · SOD-123
MMSZ5251B from Slkor SLKORMICRO Elec, 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 | Zener cathode terminal of the SOD-123 package; the device is rated for total power dissipation of max. 500 mW and an operating and storage range of -55 to +150 °C. |
| 2 | Anode | passive | Zener anode terminal of the SOD-123 package, forming the reverse-biased zener junction with the cathode; the same 500 mW and -55 to +150 °C limits apply. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Slkor SLKORMICRO Elec |
| 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) at IZT | VZT | 20.9 | 22 | 23.1 | V | IZT = 5.6 mA; VZT tested with pulses (20 ms) | 2 |
| Dynamic impedance at IZT | ZZT | 29 | Ω | at IZT = 5.6 mA | 2 | ||
| Reverse current | IR | 0.1 | µA | at VR = 17 V | 2 | ||
| Knee dynamic impedance | ZZK | 600 | Ω | at IZK = 0.25 mA | 2 | ||
| Zener voltage tolerance | -5 | 5 | % | Printed as 'Tolerance approximately ±5%' (features); suffix B | 1 | ||
| Total power dissipation | Ptot | 500 | mW | Ta = 25℃ (table header) | 1 | ||
| Operating and storage temperature range | Tj, Tstg | -55 | 150 | °C | 1 | ||
| Typical thermal resistance, junction to ambient | RθJA | 340 | °C/W | P.C.B. mounted with 2.0" X 2.0" (5 X 5 cm) copper area pads | 1 |
CAD (KiCad official)
- Symbol:
MMSZ5251B - Footprint:
Diode_SMD:D_SOD-123F - 3D model: SOD-123 (KiCad packages3D, STEP)
- 3D model files:
mmsz5251b-etched.step/mmsz5251b-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);mmsz5251b.step/mmsz5251b.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Slkor SLKORMICRO Elec datasheet (3 pp, sha256
7c7f49081d6dd25f, 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).
# MMSZ5251B
**Slkor SLKORMICRO Elec** · Zener Diodes · SOD-123
MMSZ5251B from Slkor SLKORMICRO Elec, 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 | Zener cathode terminal of the SOD-123 package; the device is rated for total power dissipation of max. 500 mW and an operating and storage range of -55 to +150 °C. |
| 2 | Anode | passive | Zener anode terminal of the SOD-123 package, forming the reverse-biased zener junction with the cathode; the same 500 mW and -55 to +150 °C limits apply. |
## Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Slkor SLKORMICRO Elec |
| 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) at IZT | VZT | 20.9 | 22 | 23.1 | V | IZT = 5.6 mA; VZT tested with pulses (20 ms) | 2 |
| Dynamic impedance at IZT | ZZT | | | 29 | Ω | at IZT = 5.6 mA | 2 |
| Reverse current | IR | | | 0.1 | µA | at VR = 17 V | 2 |
| Knee dynamic impedance | ZZK | | | 600 | Ω | at IZK = 0.25 mA | 2 |
| Zener voltage tolerance | | -5 | | 5 | % | Printed as 'Tolerance approximately ±5%' (features); suffix B | 1 |
| Total power dissipation | Ptot | | | 500 | mW | Ta = 25℃ (table header) | 1 |
| Operating and storage temperature range | Tj, Tstg | -55 | | 150 | °C | | 1 |
| Typical thermal resistance, junction to ambient | RθJA | | 340 | | °C/W | P.C.B. mounted with 2.0" X 2.0" (5 X 5 cm) copper area pads | 1 |
## CAD (KiCad official)
- Symbol: `MMSZ5251B`
- Footprint: `Diode_SMD:D_SOD-123F`
- 3D model: SOD-123 (KiCad packages3D, STEP)
- 3D model files: `mmsz5251b-etched.step` / `mmsz5251b-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `mmsz5251b.step` / `mmsz5251b.glb` are the bare package body.
## Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- **Datasheet:** [Slkor SLKORMICRO Elec datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8588916731355652096) (3 pp, sha256 `7c7f49081d6dd25f`, retrieved 2026-10-17, 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/mmsz5251b-datasheet.pdf)