# KY3401

**KY** · MOSFETs · SOT-23

KY3401 from KY, 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 | GATE | input | Gate terminal of the P-channel MOSFET; the gate-source voltage VGSS is rated ±12 V. |
| 2 | SOURCE | passive | Source terminal of the P-channel MOSFET; the datasheet gives no pin-specific limit, and the device is rated VDSS -30 V with continuous ID -4.2 A at Ta=25°C. |
| 3 | DRAIN | passive | Drain terminal of the P-channel MOSFET; the drain-source voltage VDSS is rated -30 V and continuous drain current is -4.2 A at Ta=25°C. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | KY |
| Package | SOT-23 |
| Category | Transistors/Thyristors |
| 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 |
|---|---|---|---|---|---|---|---|
| Drain-Source Voltage | VDSS |  |  | -30 | V |  | 1 |
| Gate-Source Voltage | VGSS | -12 |  | 12 | V |  | 1 |
| Continuous Drain Current | ID |  |  | -4.2 | A | Ta = 25℃ | 1 |
| Continuous Drain Current | ID |  |  | -2.7 | A | Ta = 100℃ | 1 |
| Pulsed Drain Current | IDM |  |  | -30 | A | note1 | 1 |
| Power Dissipation | PD |  |  | 1.5 | W | Ta = 25℃ | 1 |
| Thermal Resistance, Junction to Ambient | RθJA |  |  | 83 | ℃/W |  | 1 |
| Operating and Storage Temperature Range | TJ, TSTG | -55 |  | 150 | ℃ |  | 1 |
| Drain-Source Breakdown Voltage | V(BR)DSS | -30 |  |  | V | VGS=0V, ID= -250μA | 2 |
| Zero Gate Voltage Drain Current | IDSS |  |  | -1 | μA | VDS = -30V, VGS = 0V | 2 |
| Gate to Body Leakage Current | IGSS | -100 |  | 100 | nA | VDS =0V, VGS = ±12V | 2 |
| Gate Threshold Voltage | VGS(th) | -0.6 | -0.9 | -1.3 | V | VDS= VGS, ID=-250μA | 2 |
| Static Drain-Source on-Resistance | RDS(on) |  | 45 | 55 | mΩ | VGS =-10V, ID =-4A | 2 |
| Static Drain-Source on-Resistance | RDS(on) |  | 53 | 68 | mΩ | VGS =-4.5V, ID =-3A | 2 |
| Static Drain-Source on-Resistance | RDS(on) |  | 72 | 96 | mΩ | VGS =-2.5V, ID =-1A | 2 |
| Maximum Continuous Drain to Source Diode Forward Current | IS |  |  | -4.2 | A |  | 2 |
| Maximum Pulsed Drain to Source Diode Forward Current | ISM |  |  | -30 | A |  | 2 |
| Drain to Source Diode Forward Voltage | VSD |  | -0.8 | -1.2 | V | VGS = 0V, IS = -4.2A | 2 |

## CAD (KiCad official)

- Symbol: `KY3401`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `ky3401-etched.step` / `ky3401-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ky3401.step` / `ky3401.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [KY datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590233648210477056) (5 pp, sha256 `25a4939fc66b98d8`, retrieved 2026-10-17, 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/ky3401-datasheet.pdf)