HG1509-3.3M from HGSEMI, 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 4.5 V to 42 V DC. Bypass VIN to GND with a suitably large capacitor to eliminate input noise.
2	OUTPUT	output	Power Switch Output Pin (SW). Internal switch node that drives the external inductor and Schottky diode to supply the regulated output. Rated for 2 A load current.
3	FEEDBACK	input	Feedback Pin (FB). Senses the output voltage through an external resistor divider network and regulates it. Internal feedback threshold voltage is 1.23 V.
4	ON/OFF	input	Enable Pin. Drive ON/OFF low (<0.8 V) to turn on the device, drive high (>1.4 V) to turn it off. Floating defaults to low (ON). Includes hysteresis.
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 HG1509.
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 HG1509.
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 HG1509.
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 HG1509.

Key specifications

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

Ordering variants

Same part, different packaging or reel option.

HG1509-3.3M/TR
HG1509-5.0M/TR
HG1509-12M/TR
HG1509-ADJM/TR
HG1509-3.3ME/TR
HG1509-5.0ME/TR
HG1509-12ME/TR
HG1509-ADJME/TR

CAD (KiCad official)

Symbol: HG1509-3.3M
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOP-8 (KiCad packages3D, STEP)

Provenance

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

Datasheet: HGSEMI datasheet (13 pp, sha256 36284b70ad8620c2, 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