LM2596S-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	Input supply voltage. Operating range 4.75V to 40V (LM2596) or 4.75V to 60V (LM2596HV). Absolute max 45V (LM2596) / 63V (HV). Requires a bypass capacitor (typ. 680 uF) close to the pin.
2	Output	output	Switching output pin connecting to the internal power switch. Drives the external catch diode (e.g. 1N5824) and output inductor (typ. 33 uH) of the buck converter. Rated for 3A load current.
3	GND	power_in	Ground reference for the device. Also serves as the thermal/return path; connect to the ground plane for proper heat dissipation.
4	Feedback	input	Output voltage feedback pin. For fixed 3.3V version, connect directly to the regulated output node. Absolute max -0.3V to +25V; internal feedback bias current is typ. 10 nA (adjustable version).
5	ON/OFF	input	TTL-compatible active-low shutdown input. Regulator is ON when this pin is low (< 0.6V) or floating; OFF when high (> 2V). Absolute max -0.3V to +25V. Standby quiescent current ~80 uA when OFF.

Key specifications

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

Ordering variants

Same part, different packaging or reel option.

LM2596S-3.3
LM2596HVS-3.3
LM2596T-3.3
LM2596HVT-3.3

CAD (KiCad official)

Symbol: LM2596S-3.3
Footprint: Package_TO_SOT_SMD:TO-263-5_TabPin6
3D model: TO-263-5 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`lm2596s-3-3.step`	180 KB	You want the bare part, or you mark your own boards.
`lm2596s-3-3-etched.step`	2.3 MB	You want the part with `LM2596S-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: 583 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 26d031e9696524e9, 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