SSP9459 from Shanghai Siproin Microelectronics, 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	BST	passive	Bootstrap. Positive supply for the internal floating high-side MOSFET driver. Connect a bypass capacitor between this pin and SW. BST-to-SW absolute max is 6.0V.
2	GND	power_in	Ground return. Should be routed as close as possible to the output capacitor and kept away from high-current switching paths.
3	FB	input	Feedback input. Sets output voltage via an external resistor divider from VOUT to GND. Internal reference is 0.812V (typ). A frequency-foldback comparator lowers switching frequency (to ~150kHz) when FB < 250mV to prevent current-limit runaway during short-circuit.
4	EN	input	Enable input. Pull above VENR (1.35V typ) to enable; pull below VENF (1.17V typ) to disable. A 100kΩ pull-up to IN allows automatic turn-on. Absolute max 6.0V.
5	VIN	power_in	Input supply, 4.5V to 60V operating (absolute max 62V). Powers all internal control circuits. Requires a decoupling capacitor to ground placed close to this pin to reduce switching spikes.
6	SW	output	Switch output. Drain of the internal high-side MOSFET (RDS(on) ≈ 1Ω). Connect the external inductor and catch Schottky diode here. Voltage range -0.3V to VIN(MAX)+0.3V.

Key specifications

Parameter	Value
Manufacturer	Shanghai Siproin Microelectronics
Package	SOT-23-6
Category	PMIC
Pins	6

CAD (KiCad official)

Symbol: SSP9459
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
`ssp9459.step`	97 KB	You want the bare part, or you mark your own boards.
`ssp9459-etched.step`	1.9 MB	You want the part with `SSP9459` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 437 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: Shanghai Siproin Microelectronics datasheet (8 pp, sha256 40202436a30fcb96, 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