# SZ1SMA170AT3G

**Littelfuse** · ESD And Surge Protection (TVS/ESD) · DO-214AC(SMA)

SZ1SMA170AT3G from Littelfuse, in a DO-214AC(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 of the uni-directional TVS, identified by the color band on the package; the device is rated for a working peak reverse voltage (VRWM) of 170 V and 400 W peak pulse power. |
| 2 | Anode | passive | Anode of the uni-directional TVS; at VRWM 170 V the maximum reverse leakage is 2.5 µA, and the clamping voltage is 275 V at a peak pulse current of 1.5 A. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Littelfuse |
| Package | DO-214AC(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 |
|---|---|---|---|---|---|---|---|
| Peak Power Dissipation | PPK |  |  | 400 | W | TL = 25°C, Pulse Width = 1 ms (note 1: 10 X 1000 µs, non-repetitive) | 1 |
| DC Power Dissipation @ TL = 75°C | PD |  |  | 1.5 | W | Measured zero lead length (note 2) | 1 |
| DC Power Dissipation @ TA = 25°C | PD |  |  | 0.5 | W | FR-4 board, Littelfuse minimum recommended footprint (note 3) | 1 |
| Forward Surge Current | IFSM |  |  | 40 | A | TA = 25°C, for uni-directional (note 4: 1/2 sine wave, PW = 8.3 ms) | 1 |
| Operating and Storage Temperature Range | TJ, Tstg | -65 |  | 150 | °C |  | 1 |
| Breakdown Voltage | VBR | 189 | 199 | 209 | V | @ IT = 1 mA (note 7), TA = 25°C | 3 |
| Maximum Reverse Leakage Current | IR |  |  | 2.5 | µA | @ VRWM = 170 V | 3 |
| Forward Voltage | VF |  |  | 3.5 | V | @ IF = 30 A, all types (note 5) | 2 |
| Clamping Voltage | VC |  | 275 |  | V | @ IPP = 1.5 A (note 8: surge waveform per Figure 2) | 3 |
| Junction Capacitance | C |  | 112 |  | pF | Bias voltage = 0 V, F = 1.0 MHz, TJ = 25°C (note 9) | 3 |
| Working Peak Reverse Voltage | VRWM |  | 170 |  | V | Note 6: should be equal to or greater than DC or continuous peak operating voltage | 3 |
| Thermal Resistance from Junction-to-Lead | RθJL |  | 50 |  | °C/W | Measured zero lead length, 1 in square copper pad, FR-4 (note 2) | 1 |
| Thermal Resistance from Junction-to-Ambient | RθJA |  | 250 |  | °C/W | FR-4 board, minimum recommended footprint (note 3) | 1 |
| DC Power Derating above 75°C | PD |  | 20 |  | mW/°C | Derate above TL = 75°C | 1 |
| DC Power Derating above 25°C | PD |  | 4 |  | mW/°C | Derate above TA = 25°C | 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 | and the terminal finish material is tin(Sn) (IPC/ | 1 |

## CAD (KiCad official)

- Symbol: `SZ1SMA170AT3G`
- Footprint: `Diode_SMD:D_SMA`
- 3D model: DO-214AC(SMA) (KiCad packages3D, STEP)
- 3D model files: `sz1sma170at3g-etched.step` / `sz1sma170at3g-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `sz1sma170at3g.step` / `sz1sma170at3g.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/8590476206765207552) (7 pp, sha256 `2dcbd1b5c6bf6a05`, retrieved 2026-10-16, 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/sz1sma170at3g-datasheet.pdf)