AZ431AN-ATRG1 from Diodes Incorporated, 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 to the internal error amplifier. The device regulates so that V(REF) equals the internal 2.5 V bandgap reference. Reference input current range is +/-10 mA absolute max; typical bias current is in the microamp range. Connect to the tap of the external resistor divider from CATHODE to ANODE that sets the shunt regulation voltage: V_KA = (1 + R1/R2) * V_REF.
2	CATHODE	passive	Cathode of the shunt regulator (equivalent to a programmable Zener cathode). Sinks the regulated current (I_KA) from the load through an internal pass transistor when V_KA reaches the programmed threshold. Rated V_KA up to 40 V absolute max (36 V recommended), continuous cathode current -100 to +150 mA absolute max (1-100 mA recommended operating).
3	ANODE	passive	Anode of the shunt regulator; the internal reference and error amplifier ground return. Connect to the negative side of the shunt (typically circuit ground / the low side of the R1/R2 divider).

Key specifications

Parameter	Value
Manufacturer	Diodes Incorporated
Package	SOT-23
Category	PMIC
Pins	3

Ordering variants

AZ431AN-ATRG1
AZ431AN-ATRG1AZ431ANTR-G1

CAD (KiCad official)

Symbol: AZ431AN-ATRG1
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
`az431an-atrg1.step`	59 KB	You want the bare part, or you mark your own boards.
`az431an-atrg1-etched.step`	1.7 MB	You want the part with `AZ431AN-ATRG1` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 445 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: Diodes Incorporated datasheet (19 pp, sha256 af7f4848d81a3997, 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