PT4115B89E from PowTech CR PowTech Shanghai, in a SOT-89-5. 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	SW	output	Switch output. Drain of the internal high-side N-channel MOSFET switch (Rds(on) ~0.4-0.6 Ω, Isw <=1.2 A continuous, absolute max 1.5 A, -0.3 to 45 V). Connects to the inductor (and the freewheel diode cathode) in the buck power stage.
2	GND	power_in	Signal and power ground. Connect directly to the ground plane; also serves as the return for the internal MOSFET switch current.
3	DIM	input	Logic-level dimming / enable input. Drive below 0.3 V to disable the current regulator (shutdown, Iq ~95 µA); drive >=2.5 V to enable full LED current. Accepts a DC voltage from 0.5-2.5 V for linear brightness control, or a PWM signal from 100 Hz up to 20 kHz for duty-cycle dimming (5000:1 range). Internally pulled to a 5 V rail via a ~200 kΩ resistor, so the pin may be left floating for always-on operation. Absolute max -0.3 to 6 V.
4	CSN	input	High-side current-sense input. Connects to the low side of the external sense resistor Rs (which sits between VIN and CSN). The internal comparator regulates the average voltage (VIN - VCSN) to ~100 mV (98 mV A-type / 102 mV B-type), giving ILED_avg ≈ 0.1 V / Rs. Input current ~8 µA; absolute max +0.3 V to -6.0 V with respect to VIN.
5	VIN	power_in	Input supply pin. Operating range 6 V to 30 V (absolute max -0.3 to 45 V); UVLO ~5.1 V with ~500 mV hysteresis. Must be locally bypassed (typ. 100 µF ceramic/electrolytic to GND close to the pin). Also serves as the high-side reference for the current-sense comparator.

Key specifications

Parameter	Value
Manufacturer	PowTech CR PowTech Shanghai
Package	SOT-89-5
Category	LED-drv
Pins	5

Ordering variants

Same part, different packaging or reel option.

PT4115B89E
PT4115B89E-B
PT4115BSOH
PT4115BSOH-B

CAD (KiCad official)

Symbol: PT4115B89E
Footprint: Package_TO_SOT_SMD:SOT-89-5
3D model: SOT-89-5 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`pt4115b89e.step`	86 KB	You want the bare part, or you mark your own boards.
`pt4115b89e-etched.step`	1.6 MB	You want the part with `PT4115B89E` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 415 faces against 26 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: PowTech CR PowTech Shanghai datasheet (18 pp, sha256 24a8e87d81cf2d2d, 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