BL9161G-33BARN from BL Shanghai Belling, in a SOT-23-5. 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	Power input voltage. Operating range 2.2V to 6V (absolute max -0.3V to +6V). Bypass with ≥1µF ceramic capacitor located within 0.5 inch of the pin.
2	GND	power_in	Device ground. Should be the common return for VIN and VOUT bypass capacitors; separate VIN/VOUT ground planes are recommended, joined only at this pin.
3	EN	input	Chip enable input. Active high with an internal pull-down resistor (suffix 'A'). VIH ≥ 1.2V turns the LDO on; VIL ≤ 0.4V places it in shutdown (typ 0.01µA ISTBY). May be tied to VIN for always-on operation.
4	NC	unconnected	No internal connection. May be left floating or tied to ground for improved PCB layout.
5	VOUT	power_out	Regulated output voltage (3.3V for the -33 option, ±2% accuracy). Delivers up to 300mA with 205mV dropout at 300mA. Requires a ≥1µF ceramic output capacitor (ESR > 25mΩ) for stability; a fast output discharge circuit pulls VOUT down when EN is de-asserted.

Key specifications

Parameter	Value
Manufacturer	BL Shanghai Belling
Package	SOT-23-5
Category	PMIC
Pins	5

Ordering variants

BL9161G-33BARN
BL9161G-33BARNURN
BL9161G-33BARNRT
BL9161G-33BARNDRN

CAD (KiCad official)

Symbol: BL9161G-33BARN
Footprint: Package_TO_SOT_SMD:SOT-23-5
3D model: SOT-23-5 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`bl9161g-33barn.step`	85 KB	You want the bare part, or you mark your own boards.
`bl9161g-33barn-etched.step`	2.6 MB	You want the part with `BL9161G-33BARN` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 631 faces against 102 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 (12 pp, sha256 80128448c1757d7f, 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