LTL431ALT1G from LRC, in a SOT-23. 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	CATHODE	passive	Cathode (K) of the shunt reference. Sinks the regulation current; Vka may range from Vref (~2.5 V) up to 36 V max with cathode current 1 mA to 100 mA (absolute max -100 to +150 mA).
2	REF	input	Reference input (R). High-impedance sense input to the internal error amplifier; regulates when V(REF) = Vref (~2.495 V typ). Typical bias current 1.5 uA (max 4 uA).
3	ANODE	passive	Anode (A) of the shunt reference. Common return terminal for cathode and reference currents; typically tied to circuit ground in shunt-regulator applications.

Key specifications

Parameter	Value
Manufacturer	LRC
Package	SOT-23
Category	PMIC
Pins	3

Ordering variants

Same part, different packaging or reel option.

LTL431ALT1G
LTL431BLT1G
LTL431APLT1G
LTL431BPLT1G
LTL431ATLT1G
LTL431BTLT1G
LTL431APTLT1G
LTL431BPTLT1G

CAD (KiCad official)

Symbol: LTL431ALT1G
Footprint: Package_TO_SOT_SMD:SOT-23
3D model: SOT-23 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`ltl431alt1g.step`	59 KB	You want the bare part, or you mark your own boards.
`ltl431alt1g-etched.step`	1.3 MB	You want the part with `LTL431ALT1G` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 346 faces against 69 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: LRC datasheet (5 pp, sha256 8d4aaa62f4bc7d35, 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