LTL431ATSLT1G 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) terminal of the shunt regulator. Sinks current (typ 1-100 mA, absolute max -100 to +150 mA) to regulate the cathode-to-anode voltage. Cathode voltage may be set from Vref (~2.5V) up to 36V. Dynamic impedance ~0.2 Ω.
2	REF	input	Reference (R) input pin. Internally compared against the 2.5V bandgap reference; the device regulates so that this pin sits at Vref (typ 2.495-2.50 V). Typical reference input current ~1 µA (max 2 µA). Connect to the R1/R2 divider from cathode to set output voltage: VKA = Vref x (1 + R1/R2) + Iref x R1.
3	ANODE	passive	Anode (A) terminal, typically tied to circuit ground / return. Return path for the cathode sink current and the internal reference amplifier.

Key specifications

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

Ordering variants

Same part, different packaging or reel option.

LTL431ATSLT1G
LTL431BTSLT1G
LTL431APTSLT1G
LTL431BPTSLT1G

CAD (KiCad official)

Symbol: LTL431ATSLT1G
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
`ltl431atslt1g.step`	59 KB	You want the bare part, or you mark your own boards.
`ltl431atslt1g-etched.step`	1.6 MB	You want the part with `LTL431ATSLT1G` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 421 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 a9ab6fd3d1d0d015, 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