TX4221 from XDS, in a SOP-8. 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	DRV	output	Gate drive output for the external power MOSFET. Rise/fall time ~50 ns into 500 pF; absolute maximum 8 V.
2	VDD	power_in	Chip supply input. Operating range 5-40 V (absolute max 45 V). UVLO threshold ~4.8 V; operating current ~2.5 mA at 200 kHz.
3	EN	input	Chip enable, active high. VIH >= 3.2 V, VIL <= 0.8 V. Absolute max 45 V. Pulling EN low puts the chip in standby (~75 uA).
4	ROSC	input	External resistor to GND sets the switching frequency: Fs = 4.83e7 / (ROSC + 1.08e5) Hz. With ROSC tied directly to GND the internal frequency defaults to ~450 kHz; typical values 100-330 kOhm (150 kHz at 330 kOhm).
5	FB	input	Output voltage feedback pin. Internal reference V_FB = 1.000 V (975-1025 mV). Vout = (R1+R2)/R1 * V_FB. Absolute max 6.5 V.
6	NC	unconnected	No connection; leave floating (悬空).
7	GND	power_in	Device ground reference.
8	VCS	input	MOSFET switch current-limit sense input. Over-current threshold typ. 250 mV (240-260 mV). Peak inductor current IPK <= 0.25 / R_CS. Absolute max 6.5 V.

Key specifications

Parameter	Value
Manufacturer	XDS
Package	SOP-8
Category	PMIC
Pins	8

CAD (KiCad official)

Symbol: TX4221
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOP-8 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`tx4221.step`	122 KB	You want the bare part, or you mark your own boards.
`tx4221-etched.step`	1.2 MB	You want the part with `TX4221` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 324 faces against 147 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: XDS datasheet (6 pp, sha256 baf00f6a9445dd43, 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