L78L33ACD13TR 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	VOUT	power_out	Regulated 3.3 V DC output (typ. 3.3 V, min 2.97 V, max 3.63 V over 1-70 mA). Requires a 0.1 uF ceramic output capacitor to ground for stability. Delivers up to 100 mA.
2	GND	power_in	Ground reference. In the SO-8 package pins 2, 3, 6 and 7 are internally commoned to the die attach flag to improve thermal dissipation; all four should be tied to the ground plane with a copper heat-sink area (approx. 6 cm^2) for the specified thermal resistance.
3	GND	power_in	Ground / thermal pad connection. Internally commoned to the die attach flag together with pins 2, 6 and 7.
4	NC	unconnected	No internal connection. Leave floating or tie to ground for lowest parasitic coupling.
5	NC	unconnected	No internal connection. Leave floating or tie to ground for lowest parasitic coupling.
6	GND	power_in	Ground / thermal pad connection. Internally commoned to the die attach flag together with pins 2, 3 and 7.
7	GND	power_in	Ground / thermal pad connection. Internally commoned to the die attach flag together with pins 2, 3 and 6.
8	VIN	power_in	Unregulated DC input. Absolute maximum 30 V for 3.3 V output variants; recommended operating range 5.3 V to 20 V (dropout typ. 2 V). A 0.33 uF ceramic input capacitor to ground is required close to the pin when the device is far from the bulk filter capacitor.

Key specifications

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

Ordering variants

Same part, different packaging or reel option.

L78L33ACD13TRD
L78L33ACD13TRD-TR
L78L33ACD13TR
L78L33ACD13TRZ
L78L33ACD13TRAZ
L78L33ACD13TRACZ
L78L33ACD13TRACUTR

CAD (KiCad official)

Symbol: L78L33ACD13TR
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
`l78l33acd13tr.step`	122 KB	You want the bare part, or you mark your own boards.
`l78l33acd13tr-etched.step`	2.5 MB	You want the part with `L78L33ACD13TR` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 621 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 (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