# BT131

**KY** · Thyristors (SCR)/Modules · TO-92

BT131 from KY, in a TO-92. 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 | T1 | passive | Main terminal T1 of the triac (T1(1) in the symbol), the current return terminal for a 1A RMS on-state current at Tc=110°C. |
| 2 | T2 | passive | Main terminal T2 of the triac (T2(2) in the symbol), rated for 600V to 800V repetitive peak off-state voltage VDRM/VRRM. |
| 3 | G | input | Gate trigger terminal (G(3) in the symbol), with gate trigger voltage VGT ≤1.2V and gate trigger current IGT ≤3mA (quadrants I, II, III) or ≤7mA (quadrant IV) at VD=12V. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | KY |
| Package | TO-92 |
| 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 |
|---|---|---|---|---|---|---|---|
| Repetitive Peak Off-State Voltage | VDRM / VRRM | 600 |  | 800 | V |  | 3 |
| R.M.S On-State Current | IT(RMS) |  |  | 1 | A | Tc=110°C | 3 |
| Surge On-State Current | ITSM |  |  | 12 | A | Tp=10ms | 3 |
| I²t for fusing | I²t |  |  | 0.72 | A²s | Tp=10ms | 3 |
| Average Gate Power Dissipation | PG(AV) |  |  | 0.3 | W | Tj=125°C | 3 |
| Peak Gate Current | IGM |  |  | 1.2 | A | tp=20us Tj=125°C | 3 |
| Operating Junction Temperature | Tj | -40 |  | 125 | °C |  | 3 |
| Storage Temperature | TSTG | -40 |  | 150 | °C |  | 3 |
| Repetitive Peak Off-State Current | IDRM |  |  | 10 | uA | Tj=25°C | 3 |
| Repetitive Peak Off-State Current | IDRM |  |  | 200 | uA | Tj=110°C | 3 |
| Repetitive Peak Reverse Current | IRRM |  |  | 10 | uA | Tj=25°C | 3 |
| Repetitive Peak Reverse Current | IRRM |  |  | 200 | uA | Tj=110°C | 3 |
| Forward on voltage | VTM |  |  | 1.5 | V | IT=1.6A tp=380us | 3 |
| Gate non-trigger voltage | VGD | 0.2 |  |  | V | VD=VDRM, Tj=110°C | 3 |
| Holding current (quadrants I,II,III) | IH |  |  | 5 | mA | VD=12V ,IGT=0.1A | 3 |
| Holding current (quadrant IV) | IH |  |  | 10 | mA | VD=12V ,IGT=0.1A | 3 |
| Gate trigger voltage | VGT |  |  | 1.2 | V | VD=12V | 3 |
| Gate trigger current (quadrants I,II,III) | IGT |  |  | 3 | mA | VD=12V | 3 |
| Gate trigger current (quadrant IV) | IGT |  |  | 7 | mA | VD=12V | 3 |
| Critical rate of rise of commutation current (quadrants I,II,III) | di/dt | 50 |  |  | A/us | IT=1A, IG==0.2A, dIg/dt=0.2A/us | 3 |
| Critical rate of rise of commutation current (quadrant IV) | di/dt | 10 |  |  | A/us | IT=1A, IG==0.2A, dIg/dt=0.2A/us | 3 |
| Critical rate of rise of commutation voltage | dv/dt | 30 |  |  | V/us | TJ=110°C VD=2/3VDRM | 3 |

## CAD (KiCad official)

- Symbol: `BT131`
- Footprint: `Package_TO_SOT_THT:TO-92_Inline`
- 3D model: TO-92 (KiCad packages3D, STEP)
- 3D model files: `bt131-etched.step` / `bt131-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bt131.step` / `bt131.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/8588944047574552576) (7 pp, sha256 `037718a4a7f61395`, 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/bt131-datasheet.pdf)