XL1509-5.0E1 from XLSEMI, in a SOIC-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. XL1509 operates from a 4.5V to 40V DC voltage. Bypass Vin to GND with a suitably large capacitor to eliminate noise on the input.
2	OUTPUT	output	Power Switch Output Pin (SW). Output is the switch node that supplies power to the output. Connects to the external inductor and Schottky diode of the buck converter.
3	FEEDBACK	input	Feedback Pin (FB). Through an external resistor divider network, Feedback senses the output voltage and regulates it. The feedback threshold voltage is 1.23V.
4	ON/OFF	input	Enable Pin. Drive ON/OFF pin low to turn on the device, drive it high to turn it off. Floating is default low. Threshold approximately 1.4V (OFF) / 0.8V (ON).
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	SOIC-8
Category	PMIC
Pins	8

Ordering variants

Same part, different packaging or reel option.

XL1509-5.0E1

CAD (KiCad official)

Symbol: XL1509-5.0E1
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOIC-8 (KiCad packages3D, STEP)

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: XLSEMI datasheet (13 pp, sha256 8b10b01cdcb05276, 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