COS3157ST from COSINE, in a SOT-23-6. 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	NO	bidirectional	Normally Open analog switch terminal. Connected to COM when IN = 1 (switch ON), high-impedance when IN = 0. Rail-to-rail analog signal range 0V to VCC; conducts equally well in both directions with ~4.5Ω typical ON resistance.
2	GND	power_in	Ground return for the device. 0V reference for supply and digital control input.
3	NC	bidirectional	Normally Closed analog switch terminal. Connected to COM when IN = 0 (switch ON), high-impedance when IN = 1. Rail-to-rail analog signal range 0V to VCC; conducts equally well in both directions. Note: 'NC' here means Normally Closed switch pole, not No-Connect.
4	COM	bidirectional	Common analog switch terminal. Routed to either NO or NC depending on the state of the IN control pin. Rail-to-rail signal range 0V to VCC.
5	VCC	power_in	Positive supply input. Recommended operating range 1.65V to 5.5V (absolute max 6.0V). Typical quiescent supply current ICC ≤ 5µA at 5.5V.
6	IN	input	Digital control input selecting the switch state. IN = 0 → NC-to-COM path ON, NO OFF; IN = 1 → NO-to-COM path ON, NC OFF. TTL/CMOS compatible: VIH ≥ 2.6V (5V), ≥1.7V (3.3V); VIL ≤ 0.8V (5V), ≤0.7V (3.3V). Must be held HIGH or LOW; do not leave floating.

Key specifications

Parameter	Value
Manufacturer	COSINE
Package	SOT-23-6
Category	Interface
Pins	6

Ordering variants

Same part, different packaging or reel option.

COS3157ST
COS3157STSC

CAD (KiCad official)

Symbol: COS3157ST
Footprint: Package_TO_SOT_SMD:SOT-23-6
3D model: SOT-23-6 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`cos3157st.step`	97 KB	You want the bare part, or you mark your own boards.
`cos3157st-etched.step`	1.9 MB	You want the part with `COS3157ST` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 461 faces against 117 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: COSINE datasheet (10 pp, sha256 7d3155a9f9498ff0, 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