BL1117-33CY from BL Shanghai Belling, in a TO-252-2(DPAK). 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 / device reference. Return path for quiescent current (typ. 2mA, max 5mA) and load current up to 1A. Connect directly to the system ground plane.
2	Vout	power_out	Regulated 3.3V output (min 3.234V, typ 3.3V, max 3.366V). Supplies up to 1A load current with 10mV typical load regulation. Requires a 10µF tantalum or MLCC output capacitor for stability.
3	Vin	power_in	Unregulated input supply. Operating range up to 12V (absolute max 15V). Must be ≥ Vout + 1.3V dropout at 1A. Bypass with a 10µF tantalum or MLCC capacitor as close to the pin as possible.
4	Vout(Tab)	power_out	Exposed metal tab of the TO-252 (DPAK) package. Electrically fused to pin 2 (Vout) as is standard for this device family. Solder to a large copper pour to sink heat (θJC ≈ 10°C/W); this is the primary heat-dissipation path.

Key specifications

Parameter	Value
Manufacturer	BL Shanghai Belling
Package	TO-252-2(DPAK)
Category	PMIC
Pins	4

Ordering variants

BL1117-33CY
BL1117-33CY33AY
BL1117-33CY33CX
BL1117-33CY33AX

CAD (KiCad official)

Symbol: BL1117-33CY
Footprint: Package_TO_SOT_SMD:TO-252-2
3D model: TO-252-2(DPAK) (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`bl1117-33cy.step`	119 KB	You want the bare part, or you mark your own boards.
`bl1117-33cy-etched.step`	1.7 MB	You want the part with `BL1117-33CY` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 451 faces against 83 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: BL Shanghai Belling datasheet (15 pp, sha256 a7fe7f5c0846d4ca, 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