MMTL431M from CBI, 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. Sensing input to the internal error amplifier; regulates so that V(REF) equals the internal 2.495 V bandgap. Typical reference input current 1.5 μA (max 4 μA).
2	K	passive	Cathode. Shunt-regulator output terminal; sinks 1 to 100 mA in regulation with V(KA) ranging from V(REF) up to 36 V (absolute max 37 V). Off-state leakage typ 0.05 μA at V(KA)=36 V.
3	A	passive	Anode. Common/return terminal for the shunt regulator; typically tied to circuit ground in the reference-divider configuration.

Key specifications

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

Ordering variants

Same part, different packaging or reel option.

MMTL431MM

CAD (KiCad official)

Symbol: MMTL431M
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
`mmtl431m.step`	59 KB	You want the bare part, or you mark your own boards.
`mmtl431m-etched.step`	1.1 MB	You want the part with `MMTL431M` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 294 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: CBI datasheet (3 pp, sha256 1daadd9e4fa3c494, 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