RT8289GSP from Richtek Tech, in a SOIC-8-EP. 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	BOOT	input	High Side Gate Drive Bootstrap Input. Supplies the drive for the high-side N-MOSFET switch. Connect a 10nF or greater capacitor from SW to BOOT to power the high-side switch. Absolute maximum is (VSW - 0.3V) to (VSW + 6V); typical VBOOT-SW is 4.8V.
2	NC	unconnected	No Internal Connection.
3	NC	unconnected	No Internal Connection.
4	FB	input	Feedback Input. Senses the output voltage through a resistive divider to regulate said voltage; the divider values also set loop bandwidth. Feedback threshold is 1.222V (typ).
5	EN	input	Chip Enable (Active High). Digital input that turns the regulator on/off. Drive above 1.4V to enable, below 0.4V to disable; leave open for automatic startup (1µA pull-up). Absolute max 6V; recommended 0V-5.5V.
6	GND	power_in	Ground. Both pin 6 and the exposed pad (pin 9) must be connected to GND; the exposed pad must be soldered to a large PCB copper area for maximum power dissipation.
7	VIN	power_in	Power Input. Supplies the IC and step-down converter switches. Drive with a 5.5V to 32V source (abs max 34V). Bypass to GND with a suitably large capacitor to eliminate input noise.
8	SW	power_out	Power Switching Output. Switching node that supplies power to the output; connect the output LC filter from SW to the load. A capacitor from SW to BOOT powers the high-side switch. Absolute max -0.6V to (VIN + 0.3V).
9	GND	power_in	Exposed Pad (Ground). Must be soldered to a large PCB copper area and connected to GND for maximum power dissipation; θJC = 15°C/W measured at the exposed pad.

Key specifications

Parameter	Value
Manufacturer	Richtek Tech
Package	SOIC-8-EP
Category	PMIC
Pins	9

Ordering variants

Same part, different packaging or reel option.

RT8289GSP

CAD (KiCad official)

Symbol: RT8289GSP
Footprint: Package_SO:SOIC-8-1EP_3.9x4.9mm_P1.27mm_EP2.29x3mm
3D model: SOIC-8-EP (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`rt8289gsp.step`	125 KB	You want the bare part, or you mark your own boards.
`rt8289gsp-etched.step`	2.5 MB	You want the part with `RT8289GSP` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 584 faces against 152 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: Richtek Tech datasheet (13 pp, sha256 a08c6019321dbdd5, 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