# SI4554DY

**TECH PUBLIC** · MOSFETs · SOIC-8

SI4554DY from TECH PUBLIC, in a SOIC-8. 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 the N-channel MOSFET (VDS 40V, ID 8A, RDS(ON) <19mΩ at VGS=10V). |
| 2 | G1 | input | Gate of the N-channel MOSFET (VGS ±20V max, threshold 1V min to 2.0V max at ID=250µA). |
| 3 | S2 | passive | Source of the P-channel MOSFET (VDS -40V, ID -7A, RDS(ON) <35mΩ at VGS=-10V). |
| 4 | G2 | input | Gate of the P-channel MOSFET (VGS ±20V max). |
| 5 | D2 | passive | Drain of the P-channel MOSFET (VDS -40V, pulsed IDM -30A), tied to pin 6. |
| 6 | D2 | passive | Drain of the P-channel MOSFET (VDS -40V, pulsed IDM -30A), tied to pin 5. |
| 7 | D1 | passive | Drain of the N-channel MOSFET (VDS 40V, pulsed IDM 40A), tied to pin 8. |
| 8 | D1 | passive | Drain of the N-channel MOSFET (VDS 40V, pulsed IDM 40A), tied to pin 7. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | TECH PUBLIC |
| Package | SOIC-8 |
| Category | Transistors/Thyristors |
| Pins | 8 |

## CAD (KiCad official)

- Symbol: `SI4554DY`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOIC-8 (KiCad packages3D, STEP)
- 3D model files: `si4554dy-etched.step` / `si4554dy-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `si4554dy.step` / `si4554dy.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [TECH PUBLIC datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590279076448935936) (9 pp, sha256 `5a27352d6325020b`, retrieved 2026-10-17, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (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/si4554dy-datasheet.pdf)