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LD1117ASTR

STMicroelectronics · Voltage Regulators - Linear, Low Drop Out (LDO) Regulators · SOT-223-3

LD1117ASTR from STMicroelectronics, in a SOT-223-3. 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 ADJ/GND input Adjust pin (adjustable version) - connect to a resistor divider from VOUT to set the output voltage, where VOUT = 1.25 V x (1 + R2/R1) + IADJ x R2. In fixed-voltage variants this pin is the device ground.
2 VOUT power_out Regulated output. For the adjustable LD1117ASTR (this variant), VOUT is programmed via the ADJ divider from VREF = 1.25 V. Supplies up to 1 A; requires ≥10 µF for stability. The exposed TAB is internally tied to VOUT.
3 VIN power_in Unregulated DC input supply. Absolute maximum DC input voltage 15 V. Must exceed VOUT by the dropout voltage (typ. 1.15 V at 1 A).
4 TAB power_out Thermal tab, internally connected to VOUT. Solder to a copper pour for heatsinking (SOT-223 RthJA = 110 °C/W).

Key specifications

Parameter Value
Manufacturer STMicroelectronics
Package SOT-223-3
Category PMIC
Pins 4

Ordering variants

Same part, different packaging or reel option.

  • LD1117ASTR
  • LD1117AS12TR
  • LD1117AS18TR
  • LD1117AS33TR
  • LD1117ADT-TR
  • LD1117ADT12TR
  • LD1117ADT18TR
  • LD1117ADT33TR
  • LD1117AV33

CAD (KiCad official)

  • Symbol: LD1117ASTR
  • Footprint: Package_TO_SOT_SMD:SOT-223-3_TabPin2
  • 3D model: SOT-223-3 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File Size Use it when
ld1117astr.step 64 KB You want the bare part, or you mark your own boards.
ld1117astr-etched.step 1.3 MB You want the part with LD1117ASTR already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 360 faces against 75 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 (24 pp, sha256 c2dd41daa75f2827, retrieved 2026-08-17, tier: lcsc)
  • 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