LD1117AG-AD-AB3-A-R from UTC Unisonic Tech, in a SOT-89. 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	input	Adjust pin. Ties to the internal 1.25V reference feedback node; set VOUT via external resistor divider from VOUT to ADJ to GND (VOUT = 1.25V * (1 + R2/R1) + IADJ*R2). For fixed-voltage versions this same pin is GND.
2	VOUT	power_out	Regulated output. Delivers up to 1A (LD1117A) with typical dropout of ~1.20V at 1A. Requires an output capacitor (MLCC supported) for stability.
3	VIN	power_in	Unregulated positive supply input. Absolute maximum 18V; recommended operating 15V max. Input capacitor recommended near the pin.

Key specifications

Parameter	Value
Manufacturer	UTC Unisonic Tech
Package	SOT-89
Category	PMIC
Pins	3

Ordering variants

Same part, different packaging or reel option.

LD1117AG-AD-AB3-A-R
LD1117AG-AD-AB3-A-RAA3
LD1117AG-AD-AB3-A-RTA3
LD1117AG-AD-AB3-A-RTF3
LD1117AG-AD-AB3-A-RTN3
LD1117AG-AD-AB3-A-RTND
LD1117AG-AD-AB3-A-RTQ2
LD1117AG-AD-AB3-A-RTQ3
LD1117AG-AD-AB3-A-RS08

CAD (KiCad official)

Symbol: LD1117AG-AD-AB3-A-R
Footprint: Package_TO_SOT_SMD:SOT-89-3
3D model: SOT-89 (KiCad packages3D, STEP)

Provenance

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

Datasheet: UTC Unisonic Tech datasheet (15 pp, sha256 f7f26a117cb07dc2, 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