AP1501-3.3 from UMW, in a TO-263-5. 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	VIN	power_in	Positive input supply for the IC switching regulator (4.5V to 40V operating, 45V abs max). A suitable input bypass capacitor (e.g. 680µF) must be present at this pin to minimize voltage transients and supply the switching currents needed by the regulator.
2	Output	output	Internal switch node. The voltage at this pin switches between (+VIN − VSAT) and approximately −0.5V, with a duty cycle of approximately VOUT/VIN. Drives the external inductor and catch diode. To minimize coupling to sensitive circuitry, the PC board copper area connected to this pin should be kept to a minimum. Rated to deliver 3A load current.
3	GND	power_in	Circuit ground / power return.
4	Feedback	input	Output voltage feedback input. Senses the regulated output voltage to close the internal feedback loop. On the fixed 3.3V version this pin connects directly to the output rail (internal divider sets 3.3V nominal). Abs max −0.3V to +40V.
5	ON/OFF	input	TTL-level shutdown input, active-high (active is 'Low' or floating for ON). Pulling this pin below ~1.3V (or leaving it open/tied to GND) turns the regulator ON; pulling above ~1.3V (up to 25V) shuts the regulator down, dropping quiescent current to ~80µA. Abs max −0.3V to +40V.

Key specifications

Parameter	Value
Manufacturer	UMW
Package	TO-263-5
Category	PMIC
Pins	5

Ordering variants

AP1501-3.3T5L
AP1501-3.3D2T

CAD (KiCad official)

Symbol: AP1501-3.3
Footprint: Package_TO_SOT_SMD:TO-263-2
3D model: TO-263-5 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`ap1501-3-3.step`	180 KB	You want the bare part, or you mark your own boards.
`ap1501-3-3-etched.step`	1.8 MB	You want the part with `AP1501-3.3` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 498 faces against 135 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: UMW datasheet (28 pp, sha256 d716270a9a304615, 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