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SZ1SMA20AT3G
Public Made by Adomby adom
Littelfuse TVS, SMA. 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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README
markdownSZ1SMA20AT3G
Littelfuse · TVS · SMA
SZ1SMA20AT3G 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 (polarity band) of the unidirectional TVS; connect to the protected positive line, with VRWM 20 V, VBR 22.2 V min to 24.5 V max at 1 mA, and VC 32.4 V at 12.3 A. |
| 2 | ANODE | passive | Anode of the unidirectional TVS; connect to the return/ground side of the protected line (the datasheet lists it as Pin 2, Style 1). |
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 | 22.2 | 23.35 | 24.5 | V | @ IT = 1 mA, TA = 25°C | 3 |
| Working Peak Reverse Voltage | VRWM | 20 | V | 3 | |||
| Maximum Reverse Leakage Current | IR | 2.5 | µA | @ VRWM | 3 | ||
| Clamping Voltage | VC | 32.4 | V | @ IPP = 12.3 A | 3 | ||
| Maximum Reverse Peak Pulse Current | IPP | 12.3 | A | Surge waveform per Figure 2 | 3 | ||
| Forward Voltage | VF | 3.5 | V | @ IF = 30 A, all types | 2 | ||
| Peak Power Dissipation | PPK | 400 | W | TL = 25°C, Pulse Width = 1 ms | 1 | ||
| DC Power Dissipation (lead) | PD | 1 | W | TL = 75°C, zero lead length, 1" square copper pad FR-4 | 1 | ||
| DC Power Dissipation (ambient) | PD | 0.5 | W | TA = 25°C, FR-4 board, min recommended footprint | 1 | ||
| Forward Surge Current | IFSM | 40 | A | TA = 25°C, 1/2 sine wave, PW = 8.3 ms | 1 | ||
| Operating and Storage Temperature Range | TJ, Tstg | -65 | 150 | °C | 1 | ||
| Thermal Resistance Junction-to-Lead | RJL | 50 | °C/W | 1 | |||
| Thermal Resistance Junction-to-Ambient | R0JA | 250 | °C/W | FR-4 board, min recommended footprint | 1 | ||
| Derating above 75°C | 20 | mW/°C | Above TL = 75°C | 1 | |||
| Derating above 25°C | 4 | mW/°C | Above TA = 25°C | 1 | |||
| Junction Capacitance | C | 585 | pF | Bias voltage = 0 V, F = 1.0 MHz, TJ = 25°C | 3 | ||
| Test Current | IT | 1 | mA | VBR measurement | 3 |
CAD (KiCad official)
- Symbol:
SZ1SMA20AT3G - Footprint:
Diode_SMD:D_SMA - 3D model: SMA (KiCad packages3D, STEP)
- 3D model files:
sz1sma20at3g-etched.step/sz1sma20at3g-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);sz1sma20at3g.step/sz1sma20at3g.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Littelfuse datasheet (5 pp, sha256
0efc269c31859c3d, retrieved 2026-10-23, tier: lcsc) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-sonnet-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).