component
1SMB5939BT3G
Public Made by Adomby adom
onsemi Zener Diodes, SMB. Unpolarised two-terminal part: the datasheet prints no pin numbers, so pins 1 and 2 follow the library convention, 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
markdown1SMB5939BT3G
onsemi · Zener Diodes · SMB
1SMB5939BT3G from onsemi, in a SMB. 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 | K | passive | Cathode: the banded/marked end per the datasheet; pad 1 of the KiCad diode footprint. |
| 2 | A | passive | Anode. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | onsemi |
| Package | SMB |
| 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 | 37.05 | 39 | 40.95 | V | @ IZT = 9.6 mA (for this part) | 3 |
| Zener voltage tolerance (type number designation) | -5 | 5 | % | Type numbers indicate a tolerance of ±5% | 3 | ||
| Maximum Zener Impedance | ZZT | 45 | ohm | @ IZT = 9.6 mA | 3 | ||
| Maximum Zener Impedance | ZZK | 900 | ohm | @ IZK = 0.25 mA | 3 | ||
| Reverse Leakage Current | IR | 1 | µA | @ VR = 29.7 V | 3 | ||
| Maximum DC Zener Current | IZM | 38 | mA(dc) | 3 | |||
| Reverse Zener test current | IZT | 9.6 | mA | Test current for VZ, ZZT | 3 | ||
| Forward Voltage | VF | 1.5 | V | @ IF = 200 mA(dc), for all types | 3 | ||
| Maximum Steady State Power Dissipation @ TL = 75°C | PD | 3 | W | Measured at zero lead length; derate 25 mW/°C above 75°C | 1 | ||
| Maximum Steady State Power Dissipation @ TA = 25°C | PD | 550 | mW | FR-4 board, recommended footprint (Note 1); derate 4.4 mW/°C above 25°C | 1 | ||
| Thermal Resistance Junction-to-Lead | RJL | 40 | °C/W | Junction-to-lead | 1 | ||
| Thermal Resistance Junction-to-Ambient | RJA | 226 | °C/W | Junction-to-ambient (Note 1) | 1 | ||
| Operating and Storage Temperature Range | TJ, Tstg | -65 | 150 | °C | 1 |
CAD (KiCad official)
- Symbol:
1SMB5939BT3G - Footprint:
Diode_SMD:D_SMB - 3D model: SMB (KiCad packages3D, STEP)
- 3D model files:
1smb5939bt3g-etched.step/1smb5939bt3g-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);1smb5939bt3g.step/1smb5939bt3g.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: onsemi datasheet (6 pp, sha256
e95f4deeabd8ea97, retrieved 2026-10-29, tier: manufacturer) - Extractor: parts-factory
2.0.0/extract_pins, primarycathode-band convention(convention), consensusoff(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).