HX6278KSO from HUAXIN, 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	VDD	power_in	Supply voltage input. Operating range 3.0V to 24.0V (absolute max -0.3V to 27V). Supply current typ 2.5mA. Includes reverse-bias protection.
2	OUTPUT	output	Open-collector/transistor switch output. Sinks up to 50mA (max), Vsat ≤ 500mV at 20mA when active. Off-state leakage ≤ 10µA at Vout=20V. Requires external pull-up resistor (1k-10kΩ typical).
3	GND	power_in	Ground reference pin.

Key specifications

Parameter	Value
Manufacturer	HUAXIN
Package	SOT-23
Category	Sensor
Pins	3

Ordering variants

Same part, different packaging or reel option.

HX6278KSO
HX6278KSOKUA

CAD (KiCad official)

Symbol: HX6278KSO
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
`hx6278kso.step`	59 KB	You want the bare part, or you mark your own boards.
`hx6278kso-etched.step`	1.7 MB	You want the part with `HX6278KSO` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 415 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: HUAXIN datasheet (8 pp, sha256 6206c8d50a26f3b5, retrieved 2026-08-17, tier: lcsc)
Datasheet language: Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
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