SY8401ABC from Silergy Corp, in a SOT-23-6. 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	BS	passive	Boot-strap pin supplying the high-side gate driver. Decouple to LX with a 100nF (0.1uF) low-ESR ceramic capacitor. Absolute maximum BS-LX = 4V.
2	GND	power_in	Ground pin. Also serves as the case position for θ_JC measurement on the SOT23-6 package; maximize copper area for best thermal and noise performance.
3	FB	input	Output feedback pin. Connect to the center of an external resistor divider to program the output voltage: VOUT = 0.6V × (1 + R1/R2). Reference voltage 0.594-0.606V; FB input current ±50nA max.
4	EN	input	Enable control. Pull high (>1.26V) to turn on, pull low (<0.94V) to shut down (I_SHDN < 10µA). Do not leave floating; consider a 1MΩ pull-down to GND if the driving source is high-impedance at shutdown.
5	IN	power_in	Input supply pin, 4.5V to 50V operating range (absolute maximum 55V). Decouple to GND with at least 1uF (10uF X5R low-ESR ceramic recommended) placed close to the IN/GND pins.
6	LX	power_out	Switching node / inductor pin. Connects internally to the drain of the high-side N-channel power FET (RDS(ON) = 700mΩ typ). Connect to the external inductor; minimize PCB copper area on this net to reduce EMI. Peak current limit 1.05-1.65A.

Key specifications

Parameter	Value
Manufacturer	Silergy Corp
Package	SOT-23-6
Category	PMIC
Pins	6

Ordering variants

Same part, different packaging or reel option.

SY8401ABC

CAD (KiCad official)

Symbol: SY8401ABC
Footprint: Package_TO_SOT_SMD:SOT-23-6
3D model: SOT-23-6 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`sy8401abc.step`	97 KB	You want the bare part, or you mark your own boards.
`sy8401abc-etched.step`	1.9 MB	You want the part with `SY8401ABC` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 469 faces against 117 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: Silergy Corp datasheet (10 pp, sha256 5406cac6f9b1f5fd, 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