# ESD3V3U1UT-MS

**MSKSEMI** · ESD And Surge Protection (TVS/ESD) · SOT-23

ESD3V3U1UT-MS from MSKSEMI, in a SOT-23. 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 | I/O1 | passive | Protected line 1 (diode to common pin 3); VRWM 3.3V max, VB 4V min at 1mA, IR 40µA max, CT 1.5pF max. |
| 2 | I/O2 | passive | Protected line 2 (diode to common pin 3); VRWM 3.3V max, VB 4V min at 1mA, IR 40µA max, CT 1.5pF max. |
| 3 | COMMON | passive | Common node of the two protection diodes shown on the pin diagram, shared by pins 1 and 2; 80W peak pulse power (8/20µs). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | MSKSEMI |
| Package | SOT-23 |
| Category | Circuit Protection |
| Pins | 3 |

## 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 working voltage | VRWM |  |  | 3.3 | V |  | 2 |
| Breakdown voltage | VB | 4 |  |  | V | IT = 1 mA | 2 |
| Clamping voltage at 1 A | VC@1A |  |  | 7 | V | @ 1 A | 2 |
| Clamping voltage | VC |  |  | 14 | V | @ 5 A | 2 |
| Reverse leakage current | IR |  |  | 40 | µA |  | 2 |
| Line capacitance | CT |  |  | 1.5 | pF |  | 2 |
| Peak pulse power | PPK |  |  | 80 | Watts | tp = 8/20μs | 2 |
| Lead soldering temperature | TL |  |  | 260 | ℃ | 10 sec | 2 |
| Operating temperature | TJ | -55 |  | 125 | ℃ |  | 2 |
| Storage temperature | TSTG | -55 |  | 150 | ℃ |  | 2 |

## CAD (KiCad official)

- Symbol: `ESD3V3U1UT-MS`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `esd3v3u1ut-ms-etched.step` / `esd3v3u1ut-ms-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `esd3v3u1ut-ms.step` / `esd3v3u1ut-ms.glb` are the bare package body.

## Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

- **Datasheet:** [MSKSEMI datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590181829098971136) (5 pp, sha256 `40f85f4f91f75ffb`, retrieved 2026-10-21, tier: lcsc)
- **Extractor:** `ds2sf` (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/esd3v3u1ut-ms-datasheet.pdf)