LMV431AIM5X from Texas Instruments, in a SOT-23-5. 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	NC	unconnected	No internal connection. Leave floating on the PCB.
2	NC/Anode	unconnected	Internally connected to the Anode die pad. Should be either left floating or tied to the Anode pin (pin 5) on the board.
3	Cathode	passive	Cathode terminal of the shunt regulator. Sinks the regulated shunt current (0.1-15 mA operating, 30 mA abs max) to hold the programmed voltage (VREF up to 30 V abs max, 35 V absolute). Acts like the cathode of a programmable Zener.
4	Ref	input	Reference / feedback input to the internal error amplifier. Compared against the internal 1.24 V band-gap reference; a two-resistor divider from Cathode to Anode sets the regulated cathode voltage. Reference input current ≈ 0.15 µA typ (0.5 µA max).
5	Anode	passive	Anode terminal of the shunt regulator; returns cathode shunt current. Typically tied to circuit ground (or the low-side rail of the divider network).

Key specifications

Parameter	Value
Manufacturer	Texas Instruments
Package	SOT-23-5
Category	PMIC
Pins	5

Ordering variants

Same part, different packaging or reel option.

LMV431AIM5X
LMV431AIM5XIM3
LMV431AIM5XM3
LMV431AIM5XZ

CAD (KiCad official)

Symbol: LMV431AIM5X
Footprint: Package_TO_SOT_SMD:SOT-23-5
3D model: SOT-23-5 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`lmv431aim5x.step`	85 KB	You want the bare part, or you mark your own boards.
`lmv431aim5x-etched.step`	1.6 MB	You want the part with `LMV431AIM5X` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 419 faces against 102 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: Texas Instruments datasheet (41 pp, sha256 a0a41ad7f82b495a, 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