BL8039CB5TR 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	EN	input	Enable input. Drive high (VIH >= 1.2V) to enable the converter; drive low (VIL <= 0.5V) to place the part in shutdown (IQ < 1uA). Do not leave floating.
2	GND	power_in	Device ground and power return for the internal low-side synchronous NMOS. Tie to the ground plane with a short, wide, low-inductance path.
3	SW	output	Switch node. Connects to the drains of the internal high-side PMOS and low-side NMOS. Connect the external power inductor (typ. 1uH-2.2uH) between SW and the regulated output. Keep trace short and wide to minimize EMI.
4	VIN	power_in	Supply input, 2.6V to 5.5V (8V abs max, 6.1V OVP threshold). Bypass with a low-ESR ceramic capacitor (typ. 10uF) placed as close as possible to the pin.
5	FB	input	Feedback input to the error amplifier, regulated to VREF = 0.6V (+/-2%). Connect an external resistor divider from VOUT to FB and GND to set output between 0.6V and VIN: R_TOP = R_BOTTOM * (VOUT/0.6 - 1). Feedback leakage 0.1uA typ.

Key specifications

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

Ordering variants

BL8039CB5TR

CAD (KiCad official)

Symbol: BL8039CB5TR
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
`bl8039cb5tr.step`	85 KB	You want the bare part, or you mark your own boards.
`bl8039cb5tr-etched.step`	2.5 MB	You want the part with `BL8039CB5TR` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 587 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 (7 pp, sha256 ae8ae21196a5c32f, 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