TMI3253 from TMI, in a SOT-23-6. 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 pin. Return for all internal circuitry and the low-side MOSFET source. Connect to the system ground plane with a low-impedance path.
2	LX	output	Switching node. Common connection of the internal high-side and low-side power MOSFETs; connects to the external inductor. Absolute maximum -0.3V to 20V (steady) / -4.5V to 22V (<10ns transient).
3	IN	power_in	Power supply input. 4.5V to 18V operating range (20V abs max). Bypass to GND with a low-ESR ceramic capacitor (22µF typical) placed close to the pin.
4	FB	input	Output voltage feedback input. Connect to the center tap of the external resistor divider between VOUT and GND. Regulated to VREF = 0.8V (TMI3253), 0.6V (TMI3253S), or 0.765V (TMI3253T).
5	EN	input	Enable input. Drive logic-high (>0.95V typ threshold) to enable the IC; drive logic-low to disable and enter micro-power shutdown (~5µA). Do NOT leave floating.
6	BS	passive	Bootstrap. A capacitor (typ 0.1µF) between LX and BS forms a floating supply that powers the high-side N-MOSFET gate driver. Absolute maximum 26V to GND, 6V BS-to-LX.

Key specifications

Parameter	Value
Manufacturer	TMI
Package	SOT-23-6
Category	PMIC
Pins	6

Ordering variants

Same part, different packaging or reel option.

TMI3253
TMI3253T
TMI3253S

CAD (KiCad official)

Symbol: TMI3253
Footprint: Package_TO_SOT_SMD:SOT-23-6
3D model: SOT-23-6 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`tmi3253.step`	97 KB	You want the bare part, or you mark your own boards.
`tmi3253-etched.step`	1.6 MB	You want the part with `TMI3253` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 387 faces against 117 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: TMI datasheet (16 pp, sha256 b58c2a4a18985f81, 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