SY8253ADC 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. Supplies the high-side gate driver. Decouple this pin to LX with a 0.1uF ceramic capacitor.
2	GND	power_in	Ground pin. Common return for power and signal.
3	FB	input	Output feedback pin. Connect to the center of the output resistor divider to program the output voltage: Vout = 0.6V × (1 + R1/R2). Internal reference 0.6V ±1.5%.
4	EN	input	Enable control input. Pull high (>1.5V rising threshold) to turn the regulator on; below 0.4V it is off. Do not float.
5	IN	power_in	Input supply pin, 4.5V to 23V. Decouple to GND with at least a 1uF ceramic capacitor placed close to the pin.
6	LX	power_out	Switching node. Connect to the external inductor. Internal top/bottom FETs switch this node at 500 kHz with 3A output capability.

Key specifications

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

Ordering variants

Same part, different packaging or reel option.

SY8253ADC
SY8253ADCAIC

CAD (KiCad official)

Symbol: SY8253ADC
Footprint: Package_TO_SOT_SMD:SOT-23-6
3D model: SOT-23-6 (KiCad packages3D, STEP)

Provenance

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

Datasheet: Silergy Corp datasheet (13 pp, sha256 a5a2858a74928804, 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