component
SZ1SMA18AT3G
Public Made by Adomby adom
Littelfuse ESD And Surge Protection (TVS/ESD), SMA. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
Made with KiCad 10.0 · needs KiCad 10.0 or later to open · KiCad file format 20260206
| Name | Last updated |
|---|---|
| docs | 17d ago |
| viewers | 17d ago |
| package.json | 17d ago |
| page.json | 17d ago |
| README.md | 17d ago |
| sz1sma18at3g-etched.glb | 17d ago |
| sz1sma18at3g-etched.step | 17d ago |
| sz1sma18at3g-hero.glb | 17d ago |
| sz1sma18at3g-hero.overlay.json | 17d ago |
| sz1sma18at3g.glb | 17d ago |
| sz1sma18at3g.kicad_mod | 17d ago |
| sz1sma18at3g.kicad_sym | 17d ago |
| sz1sma18at3g.lbr | 17d ago |
| sz1sma18at3g.step | 17d ago |
SZ1SMA18AT3G
Littelfuse · ESD And Surge Protection (TVS/ESD) · SMA
SZ1SMA18AT3G from Littelfuse, in a SMA. 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, identified by the polarity band on the package; this is the cathode of the uni-directional TVS diode. |
| 2 | ANODE | passive | Anode terminal of the uni-directional TVS diode, which clamps transients to the device's working peak reverse voltage and clamping limits. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Littelfuse |
| Package | SMA |
| 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 | 21.05 | 22.1 | V | @ IT = 1 mA (Note 7) | 3 |
| Maximum reverse leakage current | IR | 2.5 | µA | @ VRWM | 3 | ||
| Forward voltage | VF | 3.5 | V | @ IF = 30 A, for all types | 2 | ||
| Peak power dissipation | PPK | 400 | W | @ TL = 25°C, pulse width = 1 ms (Note 1) | 1 | ||
| DC power dissipation | PD | 1 | W | @ TL = 75°C, measured zero lead length (Note 2) | 1 | ||
| DC power dissipation | PD | 0.5 | W | @ TA = 25°C (Note 3) | 1 | ||
| Forward surge current | IFSM | 40 | A | @ TA = 25°C, 1/2 sine wave, PW = 8.3 ms (Note 4) | 1 | ||
| Operating and storage temperature range | TJ, Tstg | -65 | 150 | °C | 1 | ||
| Maximum reverse peak pulse current | IPP | 13.7 | A | Column value for this MPN (VC test current) | 3 | ||
| Clamping voltage | VC | 29.2 | V | @ IPP = 13.7 A | 3 | ||
| Working peak reverse voltage | VRWM | 18 | V | Note 6 | 3 | ||
| Typical junction capacitance | C | 645 | pF | Bias voltage = 0 V, F = 1.0 MHz, TJ = 25°C (Note 9) | 3 | ||
| Thermal resistance junction to lead | RθJL | 50 | °C/W | Measured zero lead length (Note 2) | 1 | ||
| Thermal resistance junction to ambient | RθJA | 250 | °C/W | FR-4 board, minimum recommended footprint (Note 3) | 1 | ||
| Derating above 75°C (lead) | PD | 20 | mW/°C | Derate above TL = 75°C | 1 | ||
| Derating above 25°C (ambient) | PD | 4 | mW/°C | Derate above TA = 25°C | 1 |
CAD (KiCad official)
- Symbol:
SZ1SMA18AT3G - Footprint:
Diode_SMD:D_SMA - 3D model: SMA (KiCad packages3D, STEP)
- 3D model files:
sz1sma18at3g-etched.step/sz1sma18at3g-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);sz1sma18at3g.step/sz1sma18at3g.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Littelfuse datasheet (5 pp, sha256
0efc269c31859c3d, retrieved 2026-10-16, 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).