PT4211BE23E from CRMICRO, 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	SW	output	Drain of the internal power switch. Connects to the switching node between the inductor and the freewheeling Schottky diode in the buck topology. Rated up to 45V; RDS(on) ~0.5Ω; continuous current 500mA (800mA absolute max).
2	GND	power_in	Signal and power ground reference for the device. Should be tied to a solid ground plane near the chip for noise and thermal performance.
3	DIM	input	Logic-level dimming input. DIM low disables the current regulator; DIM high enables it. Supports PWM dimming (VIH ≥ 2.5V, VIL ≤ 0.25V, up to 20kHz) and analog dimming over 0.5V-2.5V DC. Internally pulled up to VDIM (~4.5V) through RDIM ~200kΩ; may be left floating for full-current operation. Absolute max −0.3V to +6V.
4	CSN	input	Current-sense input. The external sense resistor RS is connected between CSN and VIN; the average LED current is set by IOUT = 0.2 / RS (VCSN typ 200mV, hysteresis ±15%). Absolute max relative to VIN: +0.3V to −6.0V.
5	VIN	power_in	Supply input, 5V-40V operating range (absolute max 45V). Must be bypassed with a local decoupling capacitor placed close to the pin.

Key specifications

Parameter	Value
Manufacturer	CRMICRO
Package	SOT-23-5
Category	LED-drv
Pins	5

Ordering variants

Same part, different packaging or reel option.

PT4211BE23E

CAD (KiCad official)

Symbol: PT4211BE23E
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
`pt4211be23e.step`	85 KB	You want the bare part, or you mark your own boards.
`pt4211be23e-etched.step`	1.9 MB	You want the part with `PT4211BE23E` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 480 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: CRMICRO datasheet (7 pp, sha256 b844c3d993aa67d2, retrieved 2026-08-17, tier: lcsc)
Datasheet language: Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
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