LD1117D33CTR from STMicroelectronics, in a SOIC-8. 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 / common return pin. Reference for the internal band-gap and the 3.3 V output. Quiescent current returns through this pin.
2	VOUT	power_out	Regulated 3.3 V output (typ. 3.3 V, tolerance +/-1% at 25 degC). Sources up to 800 mA continuous; requires a 10 uF minimum output capacitor for loop stability. Electrically common with the DPAK tab.
3	VIN	power_in	Unregulated DC input supply. Operating range up to 15 V (18 V absolute max when IOUT < 20 mA); a 100 nF input decoupling capacitor is recommended. Dropout is typically 1.1 V at 800 mA load.
TAB	VOUT	power_out	Exposed metal tab used as the primary thermal path to the PCB copper pour. Electrically tied to VOUT internally, so any copper it contacts is at the regulated output potential.

Key specifications

Parameter	Value
Manufacturer	STMicroelectronics
Package	SOIC-8
Category	PMIC
Pins	4

Ordering variants

Same part, different packaging or reel option.

LD1117D33CTR
LD1117DT33CTR
LD1117S33CTR
LD1117S33TR
LD1117S8-33TR
LD1117V33

CAD (KiCad official)

Symbol: LD1117D33CTR
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOIC-8 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`ld1117d33ctr.step`	122 KB	You want the bare part, or you mark your own boards.
`ld1117d33ctr-etched.step`	2.1 MB	You want the part with `LD1117D33CTR` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 532 faces against 147 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 (44 pp, sha256 1b80923ec6ca9161, 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