component
SZ1SMB18CAT3G
Public Made by Adomby adom
Littelfuse ESD And Surge Protection (TVS/ESD), SMB. Unpolarised two-terminal part: the datasheet prints no pin numbers, so pins 1 and 2 follow the library convention, KiCad symbol/footprint/3D.
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SZ1SMB18CAT3G
Littelfuse · ESD And Surge Protection (TVS/ESD) · SMB
SZ1SMB18CAT3G from Littelfuse, 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 | Littelfuse |
| Package | SMB |
| Category | Circuit Protection |
| 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 |
|---|---|---|---|---|---|---|---|
| Breakdown Voltage | VBR | 20 | 21.06 | 22.1 | V | @ IT = 1.0 mA, 25°C (Note 7) | 4 |
| Clamping Voltage | VC | 29.2 | V | @ IPP = 20.5 A (Note 8) | 4 | ||
| Maximum Reverse Peak Pulse Current | IPP | 20.5 | A | Surge per Note 8 (Figure 1) | 4 | ||
| Maximum Reverse Leakage Current | IR | 5 | µA | @ VRWM = 18 V | 4 | ||
| Working Peak Reverse Voltage | VRWM | 18 | V | Note 6: should be ≥ DC or continuous peak operating voltage | 4 | ||
| Peak Power Dissipation | PPK | 600 | W | TL = 25°C, pulse width = 1 ms (Note 1) | 1 | ||
| DC Power Dissipation | PD | 3 | W | @ TL = 75°C, measured zero lead length (Note 2) | 1 | ||
| DC Power Dissipation | PD | 0.55 | W | @ TA = 25°C (Note 3) | 1 | ||
| Operating and Storage Temperature Range | TJ, Tstg | -65 | 150 | °C | 1 | ||
| Thermal Resistance from Junction-to-Lead | RƟJL | 40 | °C/W | Measured at zero lead length (Note 2) | 1 | ||
| Thermal Resistance from Junction-to-Ambient | RƟJA | 226 | °C/W | FR-4 board, Littelfuse minimum recommended footprint (Note 3) | 1 | ||
| DC Power Derating | PD | 25 | mW/°C | Derate above 75°C | 1 | ||
| DC Power Derating | PD | 4.4 | mW/°C | Derate above 25°C (Note 3) | 1 |
CAD (KiCad official)
- Symbol:
SZ1SMB18CAT3G - Footprint:
Diode_SMD:D_SMB - 3D model: SMB (KiCad packages3D, STEP)
- 3D model files:
sz1smb18cat3g-etched.step/sz1smb18cat3g-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);sz1smb18cat3g.step/sz1smb18cat3g.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Littelfuse datasheet (7 pp, sha256
b867ff8d1ae59140, retrieved 2026-10-15, tier: lcsc) - 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).
# SZ1SMB18CAT3G
**Littelfuse** · ESD And Surge Protection (TVS/ESD) · SMB
SZ1SMB18CAT3G from Littelfuse, 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 | Littelfuse |
| Package | SMB |
| Category | Circuit Protection |
| 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 |
|---|---|---|---|---|---|---|---|
| Breakdown Voltage | VBR | 20 | 21.06 | 22.1 | V | @ IT = 1.0 mA, 25°C (Note 7) | 4 |
| Clamping Voltage | VC | | | 29.2 | V | @ IPP = 20.5 A (Note 8) | 4 |
| Maximum Reverse Peak Pulse Current | IPP | | | 20.5 | A | Surge per Note 8 (Figure 1) | 4 |
| Maximum Reverse Leakage Current | IR | | | 5 | µA | @ VRWM = 18 V | 4 |
| Working Peak Reverse Voltage | VRWM | | | 18 | V | Note 6: should be ≥ DC or continuous peak operating voltage | 4 |
| Peak Power Dissipation | PPK | | | 600 | W | TL = 25°C, pulse width = 1 ms (Note 1) | 1 |
| DC Power Dissipation | PD | | | 3 | W | @ TL = 75°C, measured zero lead length (Note 2) | 1 |
| DC Power Dissipation | PD | | | 0.55 | W | @ TA = 25°C (Note 3) | 1 |
| Operating and Storage Temperature Range | TJ, Tstg | -65 | | 150 | °C | | 1 |
| Thermal Resistance from Junction-to-Lead | RƟJL | | 40 | | °C/W | Measured at zero lead length (Note 2) | 1 |
| Thermal Resistance from Junction-to-Ambient | RƟJA | | 226 | | °C/W | FR-4 board, Littelfuse minimum recommended footprint (Note 3) | 1 |
| DC Power Derating | PD | | 25 | | mW/°C | Derate above 75°C | 1 |
| DC Power Derating | PD | | 4.4 | | mW/°C | Derate above 25°C (Note 3) | 1 |
## CAD (KiCad official)
- Symbol: `SZ1SMB18CAT3G`
- Footprint: `Diode_SMD:D_SMB`
- 3D model: SMB (KiCad packages3D, STEP)
- 3D model files: `sz1smb18cat3g-etched.step` / `sz1smb18cat3g-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `sz1smb18cat3g.step` / `sz1smb18cat3g.glb` are the bare package body.
## Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- **Datasheet:** [Littelfuse datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8588938033127436288) (7 pp, sha256 `b867ff8d1ae59140`, retrieved 2026-10-15, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins`, primary `cathode-band convention` (convention), consensus `off` (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/sz1smb18cat3g-datasheet.pdf)