# BSS138DW

**YFW** · MOSFETs · SOT-363

BSS138DW from YFW, in a SOT-363. 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 | S1 | passive | Source of MOSFET 1 (N-channel, VDS max 50V, ID 0.22A continuous). |
| 2 | G1 | input | Gate of MOSFET 1, with gate-source voltage limit of ±20V and threshold of 0.80 to 1.50V at ID=1mA. |
| 3 | D2 | passive | Drain of MOSFET 2 (VDS max 50V, ID 0.22A continuous, RDS(on) max 3.5Ω at VGS=10V). |
| 4 | S2 | passive | Source of MOSFET 2 (N-channel, VDS max 50V, ID 0.22A continuous). |
| 5 | G2 | input | Gate of MOSFET 2, with gate-source voltage limit of ±20V and threshold of 0.80 to 1.50V at ID=1mA. |
| 6 | D1 | passive | Drain of MOSFET 1 (VDS max 50V, ID 0.22A continuous, RDS(on) max 3.5Ω at VGS=10V). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | YFW |
| Package | SOT-363 |
| Category | Transistors/Thyristors |
| Pins | 6 |

## 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 | VDS |  |  | 50 | V |  | 1 |
| Continuous Gate-Source Voltage | VGSS | -20 |  | 20 | V |  | 1 |
| Continuous Drain Current | ID |  |  | 0.22 | A |  | 1 |
| Power Dissipation | PD |  |  | 0.3 | W |  | 1 |
| Thermal Resistance from Junction to Ambient | RθJA |  |  | 417 | ℃/W |  | 1 |
| Operating Temperature | Tj |  |  | 150 | ℃ |  | 1 |
| Storage Temperature | Tstg | -55 |  | 150 | ℃ |  | 1 |
| Drain-source breakdown voltage | V(BR)DSS | 50 |  |  | V | VGS = 0V, ID =250µA | 2 |
| Gate-body leakage | IGSS | -500 |  | 500 | nA | VDS =0V, VGS =±20V | 2 |
| Zero gate voltage drain current | IDSS |  |  | 0.5 | µA | VDS =50V, VGS =0V | 2 |
| Zero gate voltage drain current | IDSS |  |  | 100 | nA | VDS =30V, VGS =0V | 2 |
| Gate-threshold voltage (note 1) | VGS(th) | 0.8 |  | 1.5 | V | VDS =VGS, ID =1mA | 2 |
| Static drain-source on-resistance (note 1), VGS=10V | RDS(on) |  |  | 3.5 | Ω | VGS =10V, ID =0.22A | 2 |
| Static drain-source on-resistance (note 1), VGS=4.5V | RDS(on) |  |  | 6 | Ω | VGS =4.5V, ID =0.22A | 2 |
| Body diode forward voltage (note 1) | VSD |  |  | 1.4 | V | IS=0.44A, VGS = 0V | 2 |

## CAD (KiCad official)

- Symbol: `BSS138DW`
- Footprint: `Package_TO_SOT_SMD:SOT-363_SC-70-6`
- 3D model: SOT-363 (KiCad packages3D, STEP)
- 3D model files: `bss138dw-etched.step` / `bss138dw-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bss138dw.step` / `bss138dw.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [YFW datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8603346076443561984) (4 pp, sha256 `1514ee98107d142b`, retrieved 2026-10-18, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (text+vision), consensus `claude-opus-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/bss138dw-datasheet.pdf)