TM1903 from TM Shenzhen Titan Micro Elec, in a SOP-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	OUTR	output	Red-channel constant-current output. N-channel open-drain, sinks a fixed 14 mA when enabled, rated up to 24 V in OFF state (leakage ~0.5 uA). PWM duty controlled by R[7:0] byte, 256 levels.
2	OUTG	output	Green-channel constant-current output. N-channel open-drain, sinks a fixed 14 mA when enabled, rated up to 24 V in OFF state. PWM duty controlled by G[7:0] byte, 256 levels.
3	OUTB	output	Blue-channel constant-current output. N-channel open-drain, sinks a fixed 14 mA when enabled, rated up to 24 V in OFF state. PWM duty controlled by B[7:0] byte, 256 levels.
4	GND	power_in	Ground / power negative return. All voltages referenced to this pin.
5	DO	output	Cascade data output. Forwards subsequent 24-bit packets to the next TM1903 in the chain after this chip has latched its own 24-bit word. Push-pull CMOS output (Voh >= VDD-0.5 V at 3 mA, Vol <= 0.4 V at 10 mA). Recommended 100 ohm series resistor for protection.
6	DIN	input	Single-wire serial data input. 800 kHz NRZ-style protocol with T0H/T1H encoding; Vih >= 3.5 V, Vil <= 1.5 V at VDD=5 V. Reset is a low pulse >= 200 us. Recommended 100 ohm series resistor for protection.
7	NC	unconnected	No connect. Not internally bonded; leave floating or tie to GND.
8	VDD	power_in	Logic supply, positive rail. Recommended 4.5-6.5 V direct (typ 5.0 V); an internal 5 V shunt regulator allows operation from 6-24 V through an external series resistor sized for ~10 mA VDD current (e.g. 50 ohm at 6 V, 1.8 kohm at 24 V). Bypass with 104 (100 nF) and 105 (1 uF) capacitors close to the pin.

Key specifications

Parameter	Value
Manufacturer	TM Shenzhen Titan Micro Elec
Package	SOP-8
Category	LED-drv
Pins	8

CAD (KiCad official)

Symbol: TM1903
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOP-8 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`tm1903.step`	122 KB	You want the bare part, or you mark your own boards.
`tm1903-etched.step`	1.5 MB	You want the part with `TM1903` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 374 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: TM Shenzhen Titan Micro Elec datasheet (10 pp, sha256 6aa90463ec76d9ae, 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