KF33BD-TR from STMicroelectronics, in a SO-8. 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	VOUT	power_out	Regulated 3.3 V output. Sources up to 500 mA. Requires a 2.2 µF ceramic/tantalum capacitor to GND for loop stability.
2	GND	power_in	Device ground / return. Tie to system ground plane. Multiple GND pins on SO-8 aid thermal dissipation (RthJA = 55 °C/W).
3	GND	power_in	Device ground / return. Bond internally to the die paddle for thermal dissipation; connect to ground plane along with pins 2, 6, 7.
4	NC	unconnected	No internal connection. May be left floating or tied to GND for routing convenience.
5	INHIBIT	input	TTL-compatible shutdown logic input. Drives the regulator into a low-quiescent standby state (typ. 50 µA) when asserted; otherwise the regulator operates normally. Useful for powering down downstream circuitry to save battery power.
6	GND	power_in	Device ground / return. Connect to ground plane along with pins 2, 3, 7 for improved thermal performance.
7	GND	power_in	Device ground / return. Multiple GND pins share the die paddle for heat sinking on SO-8.
8	VIN	power_in	Unregulated DC input supply, -0.5 V to +20 V absolute maximum. Bypass locally with a 0.1 µF ceramic capacitor to GND. Dropout voltage typically 0.4 V (VIN must exceed VOUT by ~0.4 V for regulation).

Key specifications

Parameter	Value
Manufacturer	STMicroelectronics
Package	SO-8
Category	PMIC
Pins	8

Ordering variants

Same part, different packaging or reel option.

KF33BD-TR
KF33BD-TRBDT-TR

CAD (KiCad official)

Symbol: KF33BD-TR
Footprint: Package_SO:TI_SO-PowerPAD-8
3D model: SO-8 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`kf33bd-tr.step`	123 KB	You want the bare part, or you mark your own boards.
`kf33bd-tr-etched.step`	1.9 MB	You want the part with `KF33BD-TR` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 470 faces against 147 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: STMicroelectronics datasheet (21 pp, sha256 a683c58723f09c6f, retrieved 2026-08-17, tier: manufacturer)
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