MD5333 from Shanghai Mingda Microelectronics, in a SOT-89-3. 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	GND	power_in	Ground / VSS return for the regulator. Common reference for VIN and VOUT; carries load return current up to 500 mA.
2	VOUT	power_out	Regulated 3.3V ±2% output. Sourcing capability up to 500 mA. Requires an output capacitor CL of ≥2.2 µF (tantalum) or ≥10 µF (aluminum electrolytic) for stability.
3	VIN	power_in	Unregulated supply input, 3.3V + Vdrop up to 10V absolute max (12V rated abs-max in table). Bypass with CIN ≥ 1.0 µF close to the pin.

Key specifications

Parameter	Value
Manufacturer	Shanghai Mingda Microelectronics
Package	SOT-89-3
Category	PMIC
Pins	3

Ordering variants

Same part, different packaging or reel option.

MD5333
MD5333MD5-33

CAD (KiCad official)

Symbol: MD5333
Footprint: Package_TO_SOT_SMD:SOT-89-3
3D model: SOT-89-3 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`md5333.step`	57 KB	You want the bare part, or you mark your own boards.
`md5333-etched.step`	1.1 MB	You want the part with `MD5333` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 305 faces against 42 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 Mingda Microelectronics datasheet (16 pp, sha256 54cbb58cd55dcd8d, 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