RS2166XC5 from Jiangsu RUNIC Tech, in a SOT-353. 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	S	bidirectional	Source: bidirectional analog/digital signal terminal of the SPST switch. Signal range 0 to VCC (rail-to-rail); interchangeable with D - either may serve as input or output.
2	D	bidirectional	Drain: bidirectional analog/digital signal terminal of the SPST switch. Signal range 0 to VCC (rail-to-rail); interchangeable with S.
3	GND	power_in	Ground reference. Continuous current through VCC or GND limited to ±100mA (abs max).
4	SEL	input	Digital switch enable input. Logic High turns the switch ON, Logic Low turns it OFF. TTL/CMOS compatible: VIH ≥ 1.5V (5V) / 1.3V (3.3V); VIL ≤ 0.6V (5V) / 0.5V (3.3V). Input leakage ≤ 1µA. Must not be left floating.
5	VCC	power_in	Positive supply. Recommended operating range 1.8V to 5.5V; absolute max 6.0V. Quiescent supply current ICC ≤ 1µA at 5.5V.

Key specifications

Parameter	Value
Manufacturer	Jiangsu RUNIC Tech
Package	SOT-353
Category	Interface
Pins	5

Ordering variants

Same part, different packaging or reel option.

RS2166XC5
RS2166XC5XF5

CAD (KiCad official)

Symbol: RS2166XC5
Footprint: Package_TO_SOT_SMD:SOT-353_SC-70-5
3D model: SOT-353 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`rs2166xc5.step`	87 KB	You want the bare part, or you mark your own boards.
`rs2166xc5-etched.step`	2.1 MB	You want the part with `RS2166XC5` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 492 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: Jiangsu RUNIC Tech datasheet (12 pp, sha256 0f3e58f75912b0d4, 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