LM2596S-12 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. Accepts unregulated DC input; operating range 4.75V to 40V (63V absolute max for HV variant). Bypass with a low-ESR bulk capacitor (typ. 680 uF) placed close to the pin.
2	Output	output	Switching output of the internal power switch. Connects to the external catch diode (e.g., 1N5822/1N5824 Schottky), inductor (typ. 33 uH for 12V out), and output filter capacitor. Delivers up to 3A load current; saturation voltage typ. 1.16V at 3A.
3	GND	power_in	Ground reference for the regulator. Also serves as the thermal path in the TO-263 (D2PAK) surface-mount package; connect to a copper ground plane for heat dissipation.
4	Feedback	input	Output voltage feedback sense pin. For the fixed 12V variant, connect directly to the regulated output node. Internal reference sets Vout = 12V (min 11.40V, max 12.60V over temperature). Absolute maximum -0.3V to +25V.
5	ON/OFF	input	TTL-compatible shutdown control. Active low: drive low or leave floating for normal operation; drive high (>~2.2V, up to 25V max) to enter standby mode (IQ typ. 80 uA). Internal pull-down keeps the device enabled when unconnected.

Key specifications

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

Ordering variants

Same part, different packaging or reel option.

LM2596S-12
LM2596HVS-12
LM2596T-12
LM2596HVT-12

CAD (KiCad official)

Symbol: LM2596S-12
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-12.step`	180 KB	You want the bare part, or you mark your own boards.
`lm2596s-12-etched.step`	2.1 MB	You want the part with `LM2596S-12` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 538 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