LDL1117S33R from STMicroelectronics, in a SOT-223-4. 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 return. Sets the reference for the internal bandgap and feedback divider; connect directly to the system ground plane close to the input/output bypass capacitors.
2	VOUT	power_out	Regulated output voltage (3.3 V for LDL1117S33R). Delivers up to 1.2 A; requires a minimum 4.7 µF output capacitor for stability. The SOT-223 tab is internally connected to this pin and should be tied to the output copper for heatsinking.
3	VIN	power_in	Unregulated input supply, 2.5 V to 18 V (20 V AMR). Should be bypassed with at least a 1 µF ceramic capacitor placed close to the pin.

Key specifications

Parameter	Value
Manufacturer	STMicroelectronics
Package	SOT-223-4
Category	PMIC
Pins	3

Ordering variants

Same part, different packaging or reel option.

LDL1117S33R

CAD (KiCad official)

Symbol: LDL1117S33R
Footprint: Package_TO_SOT_SMD:SOT-223
3D model: SOT-223-4 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`ldl1117s33r.step`	64 KB	You want the bare part, or you mark your own boards.
`ldl1117s33r-etched.step`	1.8 MB	You want the part with `LDL1117S33R` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 452 faces against 75 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: STMicroelectronics datasheet (20 pp, sha256 387b4375ad125c24, retrieved 2026-08-17, tier: manufacturer)
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