SY8501FCC from Silergy Corp, in a SO-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	NC	unconnected	Not connected. Leave floating or tie to a copper pour as convenient; no internal bond.
2	IN	power_in	Input supply pin, 7V to 100V operating range (110V absolute maximum). Decouple this pin to GND with a low-ESR ceramic capacitor placed close to the pin.
3	EN	input	Enable control input. Accurate 1.2V rising threshold (0.8V falling); can be driven directly or programmed via a resistor divider from VIN to set the VIN turn-on voltage. Absolute max VIN+0.3V.
4	RON	input	On-time programming pin. Connect a resistor from RON to IN to set the top-switch ON time and therefore the switching frequency (Fs [kHz] = 550 / Ron [MΩ], 200kHz-1000kHz range). Absolute max 6V.
5	FB	input	Output feedback pin. Connect to the mid-point of the output resistor divider to set Vout = 1.2V*(1 + R1/R2). Reference is the internal 1.2V (typ), +/-2% accurate. Absolute max 6V.
6	VCC	power_out	Output of the internal LDO (~4V VDD rail) used to supply internal gate-drive and control circuitry. Decouple to GND with a small ceramic capacitor (CVCC). Absolute max 30V.
7	BS	passive	Boot-strap pin that supplies the high-side gate driver. Connect a 0.1uF ceramic capacitor from BS to LX to develop the bootstrap voltage above LX. Absolute max LX+6V.
8	LX	power_out	Switching node / inductor pin. Connects to the drain of the top switch and source of the bottom switch; tie to the external inductor. Absolute max VIN+0.3V.
9	GND	power_in	Exposed thermal pad on the underside of the SO8E package. Serves as the device ground return and primary thermal path; solder to a large ground copper pour on the PCB.

Key specifications

Parameter	Value
Manufacturer	Silergy Corp
Package	SO-8-EP
Category	PMIC
Pins	9

Ordering variants

Same part, different packaging or reel option.

SY8501FCC

CAD (KiCad official)

Symbol: SY8501FCC
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SO-8-EP (KiCad packages3D, STEP)

Provenance

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

Datasheet: Silergy Corp datasheet (15 pp, sha256 7f2cd8e9af381554, 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