SE8550X2-HF from Seaward Elec, 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	GND	power_in	Device ground reference. Connect to system ground with a low-impedance path; place the 1 µF input decoupling capacitor close to VIN and GND.
2	VOUT	power_out	Regulated 5.0 V output (±2% for the '2' accuracy grade). Requires a ≥1 µF ceramic capacitor to GND for stability; 10 µF recommended for lower ripple. Output current ≥200 mA typical, with fold-back short-circuit protection (~450 mA limit).
3	VIN	power_in	Unregulated supply input. Operating range VOUT+1 V to 35 V (absolute max 40 V). Requires a 1 µF ceramic capacitor to GND placed close to the pin; note in-rush transients can push VIN spike ~50% above steady-state.

Key specifications

Parameter	Value
Manufacturer	Seaward Elec
Package	SOT-23
Category	PMIC
Pins	3

Ordering variants

Same part, different packaging or reel option.

SE8550X2-HF
SE8550X1-HF
SE8550L2-HF
SE8550L1-HF
SE8550K2-HF
SE8550K1-HF

CAD (KiCad official)

Symbol: SE8550X2-HF
Footprint: Package_TO_SOT_SMD:SOT-23
3D model: SOT-23 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`se8550x2-hf.step`	59 KB	You want the bare part, or you mark your own boards.
`se8550x2-hf-etched.step`	2.0 MB	You want the part with `SE8550X2-HF` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 485 faces against 69 in the bare model. It survives export, section views, and rendering in any CAD tool, and it drops straight into KiCad or Fusion with no extra setup.

Provenance

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

Datasheet: Seaward Elec datasheet (10 pp, sha256 0cbe3738392b321a, retrieved 2026-08-17, tier: lcsc)
Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF