LD1117ADT12TR from STMicroelectronics, in a 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	ADJ/GND	power_in	Ground pin for fixed-voltage versions (LD1117ADT12 fixed 1.2 V). Shared with adjust pin function on the adjustable variant; on this fixed 1.2 V part it is connected to system ground (0 V).
2	VOUT	power_out	Regulated 1.2 V output (tolerance +/-2% at 25 C, +/-4% over full temperature range). Delivers up to 1 A. Requires a 10 uF minimum output capacitor for stability. The DPAK exposed tab is internally connected to this pin.
3	VIN	power_in	Unregulated DC input voltage, up to 15 V absolute max, 10 V recommended operating. Must be at least ~1.15 V above VOUT (dropout at 1 A) for regulation. A 100 nF input capacitor is recommended per the application circuit.
4	TAB	power_out	Exposed thermal pad on the DPAK package, internally connected to VOUT. Should be soldered to a copper pour tied to the VOUT net for heat sinking (Rth(j-c) = 8 C/W, Rth(j-a) = 100 C/W for DPAK).

Key specifications

Parameter	Value
Manufacturer	STMicroelectronics
Package	DPAK
Category	PMIC
Pins	4

Ordering variants

Same part, different packaging or reel option.

LD1117ADT12TR
LD1117ADT18TR
LD1117ADT33TR
LD1117ADT-TR
LD1117AS12TR
LD1117AS18TR
LD1117AS33TR
LD1117ASTR
LD1117AV33

CAD (KiCad official)

Symbol: LD1117ADT12TR
Footprint: Package_TO_SOT_SMD:TO-252-2
3D model: DPAK (KiCad packages3D, STEP)

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: STMicroelectronics datasheet (24 pp, sha256 c2dd41daa75f2827, 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