HT7550S-1 from UMW, in a SOT-23-5. 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	Ground reference for the regulator. Connect to system ground; the tab of SOT-89 is tied to this pin and provides the thermal path.
2	VIN	power_in	Unregulated input supply. Accepts 6V to 30V for the 7550-1 variant (V_OUT + dropout min). Bypass with 10µF close to the pin per the application circuit.
3	VOUT	power_out	Regulated 5V output (±3%, 4.85-5.15V). Up to 100mA sink; requires a 10µF output capacitor for stability.

Key specifications

Parameter	Value
Manufacturer	UMW
Package	SOT-23-5
Category	PMIC
Pins	3

Ordering variants

Same part, different packaging or reel option.

HT7550S-1S

CAD (KiCad official)

Symbol: HT7550S-1
Footprint: Package_TO_SOT_SMD:SOT-23-5
3D model: SOT-23-5 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`ht7550s-1.step`	85 KB	You want the bare part, or you mark your own boards.
`ht7550s-1-etched.step`	1.6 MB	You want the part with `HT7550S-1` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 391 faces against 102 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: UMW datasheet (15 pp, sha256 f3b47345b626e60d, 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