HX809M-4.38V from HX hengjiaxing, 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	GND	power_in	Chip ground reference (0 V). Connect to system ground.
2	RESET	output	Active-low reset output. Driven low when VCC falls below the 4.38V (±2%) threshold and held low for the 350 ms (typ) reset delay after VCC recovers. VOL ≤ 0.4V at ISINK=3.2 mA; VOH ≥ VCC-1.5V at ISOURCE=800 µA (L/M/J variants). Max output current 20 mA.
3	VCC	power_in	Chip supply / monitored input voltage. Operating range 0.9V-6.0V (absolute max 6V). The internal comparator trips RESET when VCC drops below 4.38V (±2%). Has VCC transient noise immunity.

Key specifications

Parameter	Value
Manufacturer	HX hengjiaxing
Package	SOT-23
Category	PMIC
Pins	3

CAD (KiCad official)

Symbol: HX809M-4.38V
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
`hx809m-4-38v.step`	59 KB	You want the bare part, or you mark your own boards.
`hx809m-4-38v-etched.step`	2.1 MB	You want the part with `HX809M-4.38V` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 516 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: HX hengjiaxing datasheet (4 pp, sha256 4867890d2eebb1ee, 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