BR431M from Foshan Blue Rocket Elec, 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	R	input	Reference input. The internal error amplifier compares this pin against the 2.500V internal reference; typically driven from a resistor divider between cathode and anode to set the regulated cathode voltage (VKA = (1 + R1/R2)·Vref). IREF ~1 μA typical.
2	K	passive	Cathode. Shunt terminal that sinks the regulated current (1 mA to 100 mA operating, 100 mA absolute max). Supports VKA up to 37 V; when VREF exceeds 2.5 V the cathode conducts, clamping VKA.
3	A	passive	Anode. Return terminal for cathode sink current and reference; typically tied to circuit ground/common in shunt-regulator configurations.

Key specifications

Parameter	Value
Manufacturer	Foshan Blue Rocket Elec
Package	SOT-23
Category	PMIC
Pins	3

Ordering variants

Same part, different packaging or reel option.

BR431MM

CAD (KiCad official)

Symbol: BR431M
Footprint: Package_TO_SOT_SMD:SOT-23
3D model: SOT-23 (KiCad packages3D, STEP)

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: Foshan Blue Rocket Elec datasheet (7 pp, sha256 ac51a1796cf0b933, 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