STC15F104W-35I-SOP8 from STC Micro STC15F104W 35I SOP, in a SOIC-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	P3.4/RST/T0/INT2/MCLKO	bidirectional	Port 3 bit 4. Multi-function: standard I/O (PORT3[4]), active-high external RESET input (when configured via STC-ISP), Timer 0 external clock input (T0), external interrupt 2 (INT2, falling-edge only, supports power-down wakeup), or master clock output (MCLKO) at MCLK/1, MCLK/2, or MCLK/4. Factory default is I/O.
2	VCC	power_in	Positive supply voltage. Operating range 2.5V to 5.5V (wide-voltage family). Recommend a 47µF bulk plus 0.01µF (or 0.1µF for low-frequency operation) decoupling capacitor between VCC and GND.
3	P3.5/T0CLKO/INT3	bidirectional	Port 3 bit 5. Multi-function: standard I/O (PORT3[5]), Timer 0 programmable clock output T0CLKO (divides internal system clock or external T0/P3.4 input, configurable via INT_CLKO[0]), or external interrupt 3 (INT3, falling-edge only, supports power-down wakeup).
4	GND	power_in	Power supply negative / ground reference (0V).
5	P3.0/INT4/T2CLKO	bidirectional	Port 3 bit 0. Multi-function: standard I/O (PORT3[0]), external interrupt 4 (INT4, falling-edge only, supports power-down wakeup), or Timer 2 programmable clock output T2CLKO (configurable via INT_CLKO[2]).
6	P3.1/T2	bidirectional	Port 3 bit 1. Multi-function: standard I/O (PORT3[1]) or Timer 2 external clock input (T2).
7	P3.2/INT0	bidirectional	Port 3 bit 2. Multi-function: standard I/O (PORT3[2]) or external interrupt 0 (INT0). If IT0(TCON.0)=1, INT0 responds only to falling edges; if IT0=0, INT0 responds to both rising and falling edges. Supports power-down wakeup.
8	P3.3/INT1/RSTOUT_LOW	bidirectional	Port 3 bit 3. Multi-function: standard I/O (PORT3[3]), external interrupt 1 (INT1; IT1(TCON.2)=1 for falling-edge-only, IT1=0 for both edges; supports power-down wakeup), or RSTOUT_LOW output (drives low on power-up and during reset; user-selectable high/low level after reset via software).

Key specifications

Parameter	Value
Manufacturer	STC Micro STC15F104W 35I SOP
Package	SOIC-8
Category	MCU
Pins	8

Ordering variants

Same part, different packaging or reel option.

STC15F104W-35I-SOP8
STC15F104W-35I-DIP8
STC15F104W-35I-DFN8

CAD (KiCad official)

Symbol: STC15F104W-35I-SOP8
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOIC-8 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`stc15f104w-35i-sop8.step`	122 KB	You want the bare part, or you mark your own boards.
`stc15f104w-35i-sop8-etched.step`	3.5 MB	You want the part with `STC15F104W-35I-SOP8` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 841 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: STC Micro STC15F104W 35I SOP datasheet (1473 pp, sha256 c1fab41b0006cc18, 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