CD431 from Changjing, 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). Sinks the regulating current; VKA is regulated to a value set by the external divider between cathode, reference, and anode. Absolute max VKA=36V, IKA continuous range -100 to +150mA, minimum cathode current for regulation 0.45-1.0mA.
2	REFERENCE	input	Reference input (R). Internal amplifier compares this pin against the internal 2.5V bandgap (Vref typ 2.5V, 2.475-2.525V) and adjusts cathode current to hold VREF equal to Vref. Reference input current typ 1.5µA (max 4µA).
3	ANODE	passive	Anode (A). Common/ground return for the shunt regulator; the divider that programs VKA references this pin.

Key specifications

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

CAD (KiCad official)

Symbol: CD431
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
`cd431.step`	59 KB	You want the bare part, or you mark your own boards.
`cd431-etched.step`	1008 KB	You want the part with `CD431` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 250 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: Changjing datasheet (3 pp, sha256 74c36e847d4914f5, 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