TLV431BSN1T1G 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	REF	input	Reference input (R). High-impedance sense input to the internal error amplifier, compared against the internal 1.240 V (typ) bandgap reference. Reference input current I_ref = 0.15 µA typ (0.3 µA max) with R1 = 10 kΩ. Continuous input current range: −0.05 to 10 mA.
2	A	power_in	Anode (A). Common/return terminal of the shunt regulator; the internal reference and error amplifier are ground-referenced to this pin. Cathode-to-anode voltage V_KA absolute max 18 V.
3	K	power_in	Cathode (K). Shunt/regulated terminal; sinks current from an external pull-up resistor to maintain V_KA = V_ref × (1 + R1/R2). Recommended cathode current 0.1-20 mA; absolute max cathode current −20 to 25 mA; off-state leakage 0.01 µA typ at V_KA = 6 V.

Key specifications

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

Ordering variants

Same part, different packaging or reel option.

TLV431BSN1T1G
TLV431BSN1T1GSNT1G
TLV431BSN1T1GLP
TLV431BSN1T1GLPRA
TLV431BSN1T1GLPRE
TLV431BSN1T1GLPRM
TLV431BSN1T1GLPRP

CAD (KiCad official)

Symbol: TLV431BSN1T1G
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
`tlv431bsn1t1g.step`	59 KB	You want the bare part, or you mark your own boards.
`tlv431bsn1t1g-etched.step`	1.8 MB	You want the part with `TLV431BSN1T1G` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 464 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