MT8551AT from Magn Tek, 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	VCC	power_in	Power supply input. Operating range 3.0V to 24V (absolute max 30V). Reverse-battery protected down to -16V. Recommend 100nF decoupling capacitor to GND.
2	OUT	output	Open-drain switching output. Pulls Low (VDS(ON) < 0.4V at 20mA) when
3	GND	power_in	Ground reference for the device.

Key specifications

Parameter	Value
Manufacturer	Magn Tek
Package	SOT-23
Category	Sensor
Pins	3

Ordering variants

Same part, different packaging or reel option.

MT8551AT
MT8551ATA

CAD (KiCad official)

Symbol: MT8551AT
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
`mt8551at.step`	59 KB	You want the bare part, or you mark your own boards.
`mt8551at-etched.step`	1.3 MB	You want the part with `MT8551AT` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 337 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: Magn Tek datasheet (10 pp, sha256 38399f8942581dbf, 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