component
SZ1SMB28AT3G
Public Made by Adomby adom
Littelfuse ESD And Surge Protection (TVS/ESD), SMB. 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
markdownSZ1SMB28AT3G
Littelfuse · ESD And Surge Protection (TVS/ESD) · SMB
SZ1SMB28AT3G 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 | Cathode | passive | Cathode terminal of the uni-directional TVS diode; the color band or cathode mark identifies this end, per the datasheet polarity note. |
| 2 | Anode | passive | Anode terminal of the uni-directional TVS diode, the end opposite the cathode band. |
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 | 31.1 | 32.75 | 34.4 | V | @ IT = 1.0 mA, TA = 25°C (Notes 7) | 3 |
| Maximum Reverse Leakage Current | IR | 5 | µA | @ VRWM = 28 V | 3 | ||
| Clamping Voltage | VC | 45.4 | V | @ IPP = 13.2 A (Note 8) | 3 | ||
| Maximum Reverse Peak Pulse Current | IPP | 13.2 | A | Surge waveform per Figure 1 (Note 8) | 3 | ||
| Forward Voltage | VF | 3.5 | V | @ IF = 30 A (Note 5), 1/2 sine wave PW = 8.3 ms, non-repetitive | 2 | ||
| Peak Power Dissipation | PPK | 600 | W | TL = 25°C, pulse width = 1 ms (Note 1, 10/1000 µs non-repetitive) | 1 | ||
| DC Power Dissipation @ TL | PD | 3 | W | TL = 75°C, measured zero lead length (Note 2) | 1 | ||
| DC Power Dissipation @ TA | PD | 0.55 | W | TA = 25°C, FR-4 minimum recommended footprint (Note 3) | 1 | ||
| Forward Surge Current | IFSM | 100 | A | TA = 25°C, 1/2 sine wave PW = 8.3 ms, unidirectional only (Note 4) | 1 | ||
| Operating and Storage Temperature Range | TJ, Tstg | -65 | 175 | °C | 1 | ||
| Working Peak Reverse Voltage | VRWM | 28 | V | 3 | |||
| Typical Junction Capacitance | C | 590 | pF | Bias voltage = 0 V, F = 1 MHz, TJ = 25°C (Note 9) | 3 | ||
| Derate Above 75°C (DC Power, lead) | PD | 40 | mW/°C | Derate above TL = 75°C | 1 | ||
| Thermal Resistance Junction-to-Lead | RθJL | 25 | °C/W | 1 | |||
| Derate Above 25°C (DC Power, ambient) | PD | 4.4 | mW/°C | Derate above TA = 25°C | 1 | ||
| Thermal Resistance Junction-to-Ambient | RθJA | 100 | °C/W | 1 |
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 | the terminal finish material is tin(Sn) (IPC/JEDEC J-STD609A.01) | 1 |
CAD (KiCad official)
- Symbol:
SZ1SMB28AT3G - Footprint:
Diode_SMD:D_SMB - 3D model: SMB (KiCad packages3D, STEP)
- 3D model files:
sz1smb28at3g-etched.step/sz1smb28at3g-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);sz1smb28at3g.step/sz1smb28at3g.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Littelfuse datasheet (7 pp, sha256
9b427104bf8c86ce, 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).