XL1509-3.3E1 from XLSEMI, 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	VIN	power_in	Supply Voltage Input Pin. Operates from 4.5V to 40V DC. Bypass Vin to GND with a suitably large capacitor to eliminate noise on the input. Absolute maximum -0.3 to 45V.
2	OUTPUT	output	Power Switch Output Pin (SW). Switch node connected to the internal power transistor emitter; drives the external Schottky diode and inductor to supply the regulated output. Saturation voltage typ 1.2V at Iout=2A.
3	FEEDBACK	input	Feedback Pin (FB). Through an external resistor divider network (or tied directly for the fixed 3.3V variant), FB senses the output voltage and regulates it. Internal feedback threshold voltage is 1.23V.
4	ON/OFF	input	Enable Pin. Drive ON/OFF low (<0.8V) to turn on the device, drive high (>1.4V) to turn it off. TTL-compatible with hysteresis. Floating is default low (regulator ON). Shutdown supply current typ 80 uA.
5	GND	power_in	Ground Pin. Care must be taken in layout; this pin should be placed outside of the Schottky diode-to-output-capacitor ground path to prevent switching current spikes from inducing voltage noise into XL1509.
6	GND	power_in	Ground Pin. Care must be taken in layout; this pin should be placed outside of the Schottky diode-to-output-capacitor ground path to prevent switching current spikes from inducing voltage noise into XL1509.
7	GND	power_in	Ground Pin. Care must be taken in layout; this pin should be placed outside of the Schottky diode-to-output-capacitor ground path to prevent switching current spikes from inducing voltage noise into XL1509.
8	GND	power_in	Ground Pin. Care must be taken in layout; this pin should be placed outside of the Schottky diode-to-output-capacitor ground path to prevent switching current spikes from inducing voltage noise into XL1509.

Key specifications

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

Ordering variants

Same part, different packaging or reel option.

XL1509-3.3E1
XL1509-3.3E15.0E1
XL1509-3.3E112E1
XL1509-3.3E1ADJE1

CAD (KiCad official)

Symbol: XL1509-3.3E1
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
`xl1509-3-3e1.step`	122 KB	You want the bare part, or you mark your own boards.
`xl1509-3-3e1-etched.step`	2.2 MB	You want the part with `XL1509-3.3E1` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 550 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: XLSEMI datasheet (13 pp, sha256 301858b666b868e1, 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