U3018F from UNI SEMIC, 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	NC	unconnected	No connection. Recommended to leave floating.
2	FB	input	Voltage feedback input pin. When left floating, the chip defaults to a 14.3V output; for adjustable output, connect a resistor divider from the output to this pin (internal reference V_FB_REF ≈ 2.0V).
3	Drain	passive	Drain of the internal high-voltage power MOSFET (V_BR ≈ 190V, R_dson ≈ 1.15Ω). Also used for high-voltage startup current sensing (I_HV ≈ 1-4mA at HV=150V). Absolute maximum drain voltage: -0.3 to 190V.
4	SW	passive	Switch node / internal MOSFET source. Pins 4 and 7 must be shorted together in the application (they form the chip ground/switch node connection per the datasheet).
5	VF	input	Default 14.3V feedback pin. Used for output over-voltage protection sensing; when VF > 2.4V for 3 consecutive cycles the chip enters OVP and auto-restart mode.
6	VDD	power_in	Chip supply pin, also serves as an output voltage feedback terminal. A 0.1µF ceramic decoupling capacitor is recommended. V_DD_OVP ≈ 24V, V_DD_Clamp ≈ 26V @ 10mA, absolute max 30V. Startup current I_VDD_st ≈ 100µA, operating current I_VDD_Op ≈ 800µA @ 60kHz.
7	SW	passive	Switch node / internal MOSFET source. Pins 4 and 7 must be shorted together in the application.
8	GND	power_in	Ground reference for the chip.

Key specifications

Parameter	Value
Manufacturer	UNI SEMIC
Package	SOP-8
Category	PMIC
Pins	8

Ordering variants

Same part, different packaging or reel option.

U3018F

CAD (KiCad official)

Symbol: U3018F
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
`u3018f.step`	122 KB	You want the bare part, or you mark your own boards.
`u3018f-etched.step`	1.7 MB	You want the part with `U3018F` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 411 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: UNI SEMIC datasheet (11 pp, sha256 0c971a087292f446, 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