GBI1631SMAR from GOSEMICON, 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	BOOT	power_in	Power supply for the high-side power MOSFET gate driver. Requires a 0.1µF or larger ceramic bootstrap capacitor connected between BOOT and SW. BOOT-to-SW rated 0 to 6V.
2	VIN	power_in	Power supply input, 4.5V to 60V operating range (65V absolute max). Must be locally bypassed with a ceramic input capacitor.
3	EN	input	Enable logic input; floating enables the device. High-voltage tolerant up to VIN. Precision enable thresholds 1.21V rising / 1.05V falling allow programmable UVLO via an external resistor divider from VIN.
4	RT	input	Resistor-programmed switching-frequency timing pin. Connect a resistor to GND to set fSW between 200kHz and 2.5MHz (R=200kΩ → ~500kHz typical).
5	FB	input	Buck converter output feedback sensing input. Connect a resistor divider from VOUT to FB and from FB to GND; the device regulates FB to the internal 0.8V (±1%) reference.
6	PG/SS	output	On GBI1631 this pin is the Power-Good (PG) open-drain flag; pull up with a 10kΩ to 100kΩ resistor to a logic rail or DC voltage ≤7V. On GBI1630 the same pin is SS (soft-start), where a capacitor to GND programs the soft-start time. For the GBI1631SMAR variant this pin functions as PG.
7	GND	power_in	Device ground return. Tie to the ground pour along with the thermal pad.
8	SW	output	Switching node of the buck converter; connect to the external inductor and freewheeling Schottky diode. Rated -0.6V to 65V (transient -3V, 20ns).
9	EP	power_in	Exposed thermal pad on the bottom of the eSOP-8L package. Must be soldered to the PCB ground plane for proper thermal dissipation (RθJC_bot = 3.8 °C/W).

Key specifications

Parameter	Value
Manufacturer	GOSEMICON
Package	SOP-8
Category	PMIC
Pins	9

Ordering variants

Same part, different packaging or reel option.

GBI1631SMAR
GBI1630SMAR

CAD (KiCad official)

Symbol: GBI1631SMAR
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: GOSEMICON datasheet (22 pp, sha256 d362a5d7ac69f60c, 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