AMS1117-1.2S from UMW, in a SOT-89. 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 fixed-output version. On the adjustable variant this pin is the ADJ feedback input; on the AMS1117-1.2 (fixed) it is tied internally as the device ground return.
2	VOUT	power_out	Regulated 1.2V output (1.176V to 1.224V at IOUT=10mA, VIN=3.2V, TJ=25°C). Rated for up to 1A load current. Requires a 22µF tantalum output capacitor for stability.
3	VIN	power_in	Unregulated input supply. Absolute maximum 18V; recommended operating input 12V. Typical dropout of 1.2V at 1A, so VIN must exceed VOUT by at least this margin. A 10µF input bypass capacitor is recommended.

Key specifications

Parameter	Value
Manufacturer	UMW
Package	SOT-89
Category	PMIC
Pins	3

Ordering variants

Same part, different packaging or reel option.

AMS1117-1.2SS
AMS1117-1.2S
AMS1117-1.2SCD

CAD (KiCad official)

Symbol: AMS1117-1.2S
Footprint: Package_TO_SOT_SMD:SOT-89-3
3D model: SOT-89 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`ams1117-1-2s.step`	57 KB	You want the bare part, or you mark your own boards.
`ams1117-1-2s-etched.step`	1.4 MB	You want the part with `AMS1117-1.2S` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 379 faces against 42 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 (13 pp, sha256 5ec219092aa45bd9, 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