component
MMBZ5257BQ-7-F
Public Made by Adomby adom
Diodes Incorporated Zener Diodes, SOT-23. 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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Contents
README
markdownMMBZ5257BQ-7-F
Diodes Incorporated · Zener Diodes · SOT-23
MMBZ5257BQ-7-F from Diodes Incorporated, in a SOT-23. 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 | A | passive | Anode of the Zener diode, the bottom-left terminal in the top-view device schematic. |
| 2 | NC | unconnected | Bottom-right terminal; the device schematic shows no internal connection to the diode. |
| 3 | K | passive | Cathode of the Zener diode, the single top terminal in the device schematic; for MMBZ5257B the Zener voltage is 33V nominal (31.35V to 34.65V) at IZT = 3.8mA. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Diodes Incorporated |
| Package | SOT-23 |
| Category | Diodes |
| Pins | 3 |
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 | 31.35 | 33 | 34.65 | V | IZT = 3.8mA, short duration pulse test | 3 |
| Test Current | IZT | 3.8 | mA | 3 | |||
| Maximum Zener Impedance | ZZT | 58 | Ω | @ IZT, f = 1kHz | 3 | ||
| Maximum Zener Impedance (knee) | ZZK | 700 | Ω | @ IZK = 0.25mA, f = 1kHz | 3 | ||
| Maximum Reverse Leakage Current | IR | 0.1 | µA | VR = 25V, short duration pulse test | 3 | ||
| Forward Voltage | VF | 0.9 | V | IF = 10mA, TA = +25°C | 2 | ||
| Power Dissipation | PD | 350 | mW | Mounted on FR4 PC board with recommended pad layout | 2 | ||
| Thermal Resistance, Junction to Ambient Air | RθJA | 357 | °C/W | Mounted on FR4 PC board with recommended pad layout | 2 | ||
| Operating and Storage Temperature Range | TJ, TSTG | -65 | 150 | °C | 2 |
Materials and finish
As the datasheet states them (page.json metadata.appearance; the 3D model's colours follow it).
| Part | Material | Colour / plating | Datasheet says | Page |
|---|---|---|---|---|
| contacts | tin | Terminal Connections: See Diagram Terminals: Matte Tin Finish Annealed over Alloy 42 Leadframe | 1 |
CAD (KiCad official)
- Symbol:
MMBZ5257BQ-7-F - Footprint:
Package_TO_SOT_SMD:SOT-23 - 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files:
mmbz5257bq-7-f-etched.step/mmbz5257bq-7-f-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);mmbz5257bq-7-f.step/mmbz5257bq-7-f.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Diodes Incorporated datasheet (7 pp, sha256
be3510eb4019f5d5, retrieved 2026-10-23, tier: manufacturer) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-sonnet-5-5(text+vision), consensusclaude-opus-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).