# SZP6SMB91AT3G

**Littelfuse** · ESD And Surge Protection (TVS/ESD) · SMB

SZP6SMB91AT3G 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; the color band on the package denotes the cathode, and the device is rated for 600 W peak power at 1 ms. |
| 2 | Anode | passive | Anode terminal of the uni-directional TVS, opposite the cathode band, with a maximum forward voltage of 3.5 V at 30 A IF per the datasheet. |

## 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 (unidirectional 91 V, minimum) | VBR | 86.5 |  |  | V | @ IT = 1 mA; VBR measured at 25°C (Note 7) | 3 |
| Breakdown voltage (unidirectional 91 V, maximum) | VBR |  |  | 95.5 | V | @ IT = 1 mA; VBR measured at 25°C (Note 7) | 3 |
| Breakdown voltage (unidirectional 91 V, nominal) | VBR |  | 91 |  | V | @ IT = 1 mA; VBR measured at 25°C (Note 7) | 3 |
| Peak power dissipation | PPK |  |  | 600 | W | TL = 25°C, pulse width = 1 ms (Note 1: 10/1000 µs, non-repetitive) | 1 |
| DC power dissipation (lead-referenced) | PD |  |  | 3 | W | TL = 75°C, measured zero lead length (Note 2) | 1 |
| Derating of DC power dissipation (lead-referenced) |  |  |  | 40 | mW/°C | Derate above TL = 75°C | 1 |
| DC power dissipation (ambient) | PD |  |  | 0.55 | W | TA = 25°C (Note 3, FR-4 minimum recommended footprint) | 1 |
| Derating of DC power dissipation (ambient) |  |  |  | 4.4 | mW/°C | Derate above TA = 25°C | 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 |  | 150 | °C |  | 1 |
| Thermal resistance, junction-to-lead | RƟJL |  |  | 25 | °C/W | Junction-to-lead, measured zero lead length (Note 2) | 1 |
| Thermal resistance, junction-to-ambient | RƟJA |  |  | 226 | °C/W | Junction-to-ambient (Note 3) | 1 |

## CAD (KiCad official)

- Symbol: `SZP6SMB91AT3G`
- Footprint: `Diode_SMD:D_SMB`
- 3D model: SMB (KiCad packages3D, STEP)
- 3D model files: `szp6smb91at3g-etched.step` / `szp6smb91at3g-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `szp6smb91at3g.step` / `szp6smb91at3g.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/8588938790941429760) (7 pp, sha256 `baf561fbcd6cd66c`, retrieved 2026-10-14, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (text), consensus `claude-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).

[Datasheet PDF](docs/szp6smb91at3g-datasheet.pdf)