L78M09CDT-TR from STMicroelectronics, in a TO-252-2(DPAK). 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	INPUT	power_in	Unregulated positive DC input. For a 9 V output, V_I must be at least a few volts above V_O; absolute maximum V_I = 35 V (for V_O = 5-18 V). A 0.33 uF ceramic capacitor to GND is recommended close to the pin.
2	GROUND	power_in	Common ground reference. On DPAK, pin 2 is electrically tied to the exposed heat-sink tab, which is the primary thermal path (R_thJC = 8 C/W, R_thJA = 100 C/W). Solder the tab to a copper pour for heat dissipation.
3	OUTPUT	power_out	Regulated +9 V DC output, up to 0.5 A (peak >0.5 A with adequate heatsinking). Internally current-limited and SOA-protected. A 0.1 uF ceramic capacitor to GND is recommended to improve transient response and stability.

Key specifications

Parameter	Value
Manufacturer	STMicroelectronics
Package	TO-252-2(DPAK)
Category	PMIC
Pins	3

Ordering variants

Same part, different packaging or reel option.

L78M09CDT-TRT
L78M09CDT-TRP
L78M09CDT-TR

CAD (KiCad official)

Symbol: L78M09CDT-TR
Footprint: Package_TO_SOT_SMD:TO-252-2
3D model: TO-252-2(DPAK) (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`l78m09cdt-tr.step`	119 KB	You want the bare part, or you mark your own boards.
`l78m09cdt-tr-etched.step`	1.7 MB	You want the part with `L78M09CDT-TR` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 458 faces against 83 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 (47 pp, sha256 7cee4c5f6a43332c, 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