# BSS138LT1G

**onsemi** · MOSFETs · SOT-23

BSS138LT1G from onsemi, in a SOT-23. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | GATE | input | Gate control terminal with ±20 Vdc maximum continuous voltage and 0.5-1.5 Vdc threshold voltage at 1 mA drain current. |
| 2 | SOURCE | passive | Source terminal serving as voltage reference for gate-source measurements and return current path. |
| 3 | DRAIN | passive | Drain terminal with 50 Vdc maximum rating, 200 mA continuous current at 25°C, and 800 mA pulsed current. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | onsemi |
| 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-to-Source Voltage | VDSS |  |  | 50 | Vdc |  | 1 |
| Gate-to-Source Voltage - Continuous | VGS | -20 |  | 20 | Vdc |  | 1 |
| Drain Current - Continuous | ID |  |  | 200 | mA | @ TA = 25°C | 1 |
| Pulsed Drain Current | IDM |  |  | 800 | mA | tp ≤ 10 s | 1 |
| Total Power Dissipation | PD |  |  | 225 | mW | @ TA = 25°C | 1 |
| Operating and Storage Temperature Range | TJ, Tstg | -55 |  | 150 | °C |  | 1 |
| Maximum Lead Temperature for Soldering Purposes | TL |  |  | 260 | °C | for 10 seconds | 1 |
| Thermal Resistance, Junction-to-Ambient | RθJA |  | 556 |  | °C/W |  | 1 |
| Drain-to-Source Breakdown Voltage | V(BR)DSS | 50 |  |  | Vdc | VGS = 0 Vdc, ID = 250 Adc | 2 |
| Zero Gate Voltage Drain Current | IDSS |  |  | 0.1 | Adc | VDS = 25 Vdc, VGS = 0 Vdc, 25°C | 2 |
| Zero Gate Voltage Drain Current | IDSS |  |  | 0.5 | Adc | VDS = 50 Vdc, VGS = 0 Vdc, 25°C | 2 |
| Zero Gate Voltage Drain Current | IDSS |  |  | 5 | Adc | VDS = 50 Vdc, VGS = 0 Vdc, 150°C | 2 |
| Gate-Source Leakage Current | IGSS | -0.1 |  | 0.1 | Adc | VGS = ± 20 Vdc, VDS = 0 Vdc | 2 |
| Gate-Source Threshold Voltage | VGS(th) | 0.5 |  | 1.5 | Vdc | VDS = VGS, ID = 1.0 mAdc | 2 |
| Forward Transconductance | gfs | 100 |  |  | mmhos | VDS = 25 Vdc, ID = 200 mAdc, f = 1.0 kHz | 2 |
| Input Capacitance | Ciss |  | 40 | 50 | pF | VDS = 25 Vdc, VGS = 0, f = 1 MHz | 2 |
| Output Capacitance | Coss |  | 12 | 25 | pF | VDS = 25 Vdc, VGS = 0, f = 1 MHz | 2 |
| Transfer Capacitance | Crss |  | 3.5 | 5 | pF | VDG = 25 Vdc, VGS = 0, f = 1 MHz | 2 |
| Turn-On Delay Time | td(on) |  |  | 20 | ns | VDD = 30 Vdc, ID = 0.2 Adc | 2 |
| Turn-Off Delay Time | td(off) |  |  | 20 | ns |  | 2 |

## CAD (KiCad official)

- Symbol: `BSS138LT1G`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `bss138lt1g-etched.step` / `bss138lt1g-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bss138lt1g.step` / `bss138lt1g.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [onsemi datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8586181376869060608) (5 pp, sha256 `9299f11ba9d3ebbd`, retrieved 2026-09-21, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.2`, primary `claude-haiku-4-5-20251001` (text), consensus `claude-sonnet-4-6` (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/bss138lt1g-datasheet.pdf)