# X0405C

**FUXINSEMI** · TRIACs · TO-126-3

X0405C from FUXINSEMI, in a TO-126-3. 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 | K | passive | Cathode of the SCR (K1), the return terminal for the on-state current and gate drive. |
| 2 | A | passive | Anode of the SCR (A2), which blocks VDRM/VRRM of 600/800 V and carries up to 4.0 A RMS on-state current. |
| 3 | G | input | Gate trigger input (G3) with IGT of 10 to 200 μA max at VD=12 V and VGT max 0.8 V. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | FUXINSEMI |
| Package | TO-126-3 |
| Category | Triode/MOS Tube/Transistor |
| 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 |
|---|---|---|---|---|---|---|---|
| Gate trigger current | IGT | 10 |  | 200 | μA | VD =12V RL=140Ω Tj =25℃ | 2 |
| Gate trigger voltage | VGT |  |  | 0.8 | V |  | 2 |
| Gate non-trigger voltage | VGD | 0.2 |  |  | V | VD =VDRM RGK=1kΩ Tj =110℃ | 2 |
| Latching current | IL |  |  | 6 | mA | IG=1mA RGK=1kΩ Tj =25℃ | 2 |
| Holding current | IH |  |  | 5 | mA | IT=50mA RGK=1kΩ Tj =25℃ | 2 |
| Critical-rate of rise of commutation voltage | dVD/dt | 10 |  |  | V/μs | VD=2/3VDRM RGK=1kΩ Tj =110℃ | 2 |
| Forward on voltage | VTM |  |  | 1.55 | V | ITM =8A tp=380μs | 2 |
| Repetitive Peak Off-State Current | IDRM |  |  | 5 | μA | VD =VDRM VR =VRRM Tj=25℃ | 2 |
| Repetitive Peak Reverse Current | IRRM |  |  | 0.15 | mA | Tj=110℃ | 2 |
| RMS on-state current | IT(RMS) |  |  | 4 | A |  | 2 |
| Non repetitive surge peak on-state current | ITSM |  |  | 30 | A | full cycle, F=50Hz | 2 |
| I2t value for fusing | I2t |  |  | 4.5 | A2s | tp=10ms | 2 |
| Critical rate of rise of on-state current | dIT/dt |  |  | 50 | A/μs | IG =2×IGT | 2 |
| Peak gate current | IGM |  |  | 1.2 | A |  | 2 |
| Average gate power dissipation | PG(AV) |  |  | 0.2 | W |  | 2 |
| Junction Temperature | TJ | -40 |  | 110 | ℃ |  | 2 |
| Storage Temperature | TSTG | -40 |  | 150 | ℃ |  | 2 |
| Thermal resistance junction to case | Rth(j-c) |  | 7.2 |  | ℃/W | Junction to case (AC) | 2 |
| Thermal resistance junction to ambient | Rth(j-a) |  | 100 |  | ℃/W | Junction to ambient | 2 |

## CAD (KiCad official)

- Symbol: `X0405C`
- Footprint: `Package_TO_SOT_THT:TO-126-3_Vertical`
- 3D model: TO-126-3 (KiCad packages3D, STEP)
- 3D model files: `x0405c-etched.step` / `x0405c-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `x0405c.step` / `x0405c.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [FUXINSEMI datasheet](docs/x0405c-datasheet.pdf) (4 pp, sha256 `a04e7b8c7f2ee90b`, retrieved 2026-11-05, 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/x0405c-datasheet.pdf)