LM2576S-12 from HGSEMI, 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	Unregulated DC input supply. Operating range 15V-40V for LM2576 (up to 60V for LM2576HV). Bypass with a low-ESR 100µF electrolytic close to the pin.
2	Output	power_out	Switching output from the internal 3A NPN power switch. Connect to the catch Schottky diode (e.g. 1N5822) cathode and the LC output filter (typ. 100µH + 1000µF) that produces the regulated 12V rail.
3	Ground	power_in	Device power ground / signal return. Electrically common with the exposed TAB (tab is GND) - solder both to the ground plane for the thermal path.
4	Feedback	input	Regulation feedback input to the internal error amplifier. For the fixed 12V version, tie directly to the +12V output node; the internal divider sets the 1.23V bandgap reference for regulation. Bias current ~50nA (500nA max).
5	ON/OFF	input	Active-low TTL-compatible shutdown input. Logic LOW (VIL ≤ 1.0V) or grounded = regulator ON; logic HIGH (VIH ≥ 2.2V, up to VIN) = shutdown (~50µA standby current). Do not leave floating; tie to GND for always-on operation.
TAB	GND	passive	Exposed metal tab, internally connected to pin 3 (Ground). Provides the primary thermal path (RθJC(bot) ≈ 0.4°C/W); solder to a copper ground pour sized for the required θJA.

Key specifications

Parameter	Value
Manufacturer	HGSEMI
Package	TO-263-5
Category	PMIC
Pins	6

Ordering variants

Same part, different packaging or reel option.

LM2576S-12/TR
LM2576HVS-12/TR
LM2576T-12
LM2576HVT-12
LM2576TB-12
LM2576M-12/TR
LM2576ME-12/TR
LM2576DQ4-12/TR

CAD (KiCad official)

Symbol: LM2576S-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
`lm2576s-12.step`	180 KB	You want the bare part, or you mark your own boards.
`lm2576s-12-etched.step`	1.9 MB	You want the part with `LM2576S-12` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 501 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: HGSEMI datasheet (14 pp, sha256 eddc94f04fe787be, 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