# SZ1SMA33AT3G

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

SZ1SMA33AT3G 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 (the datasheet's Style 1 pin 1 designation), and the terminal that is positive relative to the anode under transient clamping. |
| 2 | ANODE | passive | Anode terminal of the unidirectional transient voltage suppressor, opposite the cathode polarity band. |

## 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 |
|---|---|---|---|---|---|---|---|
| Reverse leakage current at VRWM (maximum) | IR |  |  | 2.5 | µA | @ VRWM = 33 V | 3 |
| Breakdown voltage | VBR | 36.7 | 38.65 | 40.6 | V | @ IT = 1 mA | 3 |
| Maximum reverse peak pulse current | IPP |  |  | 7.5 | A | Table value for this device | 3 |
| Forward voltage | VF |  |  | 3.5 | V | @ IF = 30 A (all types) | 2 |
| Clamping voltage | VC |  | 53.3 |  | V | @ IPP = 7.5 A | 3 |
| Maximum junction capacitance | C |  | 375 |  | pF | Bias 0 V, F = 1.0 MHz, TJ = 25°C | 3 |
| Working peak reverse voltage | VRWM |  | 33 |  | V |  | 3 |
| 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, FR-4 minimum recommended footprint (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 |
| 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 minimum recommended footprint (Note 3) | 1 |

## CAD (KiCad official)

- Symbol: `SZ1SMA33AT3G`
- Footprint: `Diode_SMD:D_SMA`
- 3D model: SMA (KiCad packages3D, STEP)
- 3D model files: `sz1sma33at3g-etched.step` / `sz1sma33at3g-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `sz1sma33at3g.step` / `sz1sma33at3g.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/8588940667816972288) (5 pp, sha256 `0efc269c31859c3d`, retrieved 2026-10-15, 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/sz1sma33at3g-datasheet.pdf)