L78L33ABUTR from STMicroelectronics, in a SOT-89-3. 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	VOUT	power_out	Regulated 3.3 V positive output. Nominal 3.3 V (2.97 V min, 3.63 V max over line/load/temperature for L78L33C; +/-4% for L78L33AB). Delivers up to 100 mA with adequate heat-sinking. A 0.1 uF ceramic capacitor to GND is recommended for stability and transient response.
2	GND	power_in	Common ground reference for both input and output. Also serves as the thermal path; on SOT-89 the tab (pin 2) is bonded to the die attach flag and should be soldered to a copper heat-spreader for the specified 55 C/W junction-to-ambient thermal resistance.
3	VIN	power_in	Unregulated positive DC input. Operating range approximately Vout + Vdropout (~2 V typ) up to 30 V absolute max for the 3.3 V variant. A 0.33 uF input capacitor to GND is required if the regulator is located far from the input filter capacitor.

Key specifications

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

Ordering variants

Same part, different packaging or reel option.

L78L33ABUTR
L78L33ABUTRZ
L78L33ABUTRAZ
L78L33ABUTRACZ
L78L33ABUTRD
L78L33ABUTRAD
L78L33ABUTRACD

CAD (KiCad official)

Symbol: L78L33ABUTR
Footprint: Package_TO_SOT_SMD:SOT-89-3
3D model: SOT-89-3 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`l78l33abutr.step`	57 KB	You want the bare part, or you mark your own boards.
`l78l33abutr-etched.step`	1.6 MB	You want the part with `L78L33ABUTR` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 418 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: STMicroelectronics datasheet (45 pp, sha256 43922ae159face7e, 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