TLV431ASN1T1G from onsemi, 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	Reference	input	Reference (R) input. High-impedance sense input to the internal 1.24 V bandgap reference amplifier (Iref typ 0.15 µA, max 0.3 µA). The device sinks cathode current when V(Reference) exceeds Vref (1.240 V typ) to regulate the KA voltage.
2	Cathode	passive	Cathode (K). Current-sink terminal that regulates the cathode-to-anode voltage. Rated VKA up to 18 V max, cathode current -20 to +25 mA (typ operating 0.1 mA to 20 mA). Dynamic impedance
3	Anode	passive	Anode (A). Current-return terminal, typically tied to circuit ground/common. All cathode and reference currents return through this pin.

Key specifications

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

Ordering variants

Same part, different packaging or reel option.

TLV431ASN1T1G
TLV431ASN1T1GLP
TLV431ASN1T1GLPRA
TLV431ASN1T1GLPRE
TLV431ASN1T1GLPRM
TLV431ASN1T1GLPRP

CAD (KiCad official)

Symbol: TLV431ASN1T1G
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
`tlv431asn1t1g.step`	59 KB	You want the bare part, or you mark your own boards.
`tlv431asn1t1g-etched.step`	1.7 MB	You want the part with `TLV431ASN1T1G` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 435 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: onsemi datasheet (20 pp, sha256 63404349c3607665, 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