WS3221ECY from GEC, in a TSSOP-16. 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	XEN	input	Receiver enable, active-low. Driving XEN high forces the R1OUT receiver output into a high-impedance (tri-state) condition.
2	C1P	passive	Positive terminal of the boost (doubler) charge-pump flying capacitor. Connect a 0.1 µF capacitor between C1P (pin 2) and C1N (pin 4).
3	VP	power_out	Charge-pump generated positive rail, approximately +5.4 V. Bypass to GND with a 0.1 µF capacitor; internally supplies the RS-232 driver's positive swing.
4	C1N	passive	Negative terminal of the boost charge-pump flying capacitor. Paired with C1P (pin 2) via a 0.1 µF capacitor.
5	C2P	passive	Positive terminal of the inverting charge-pump flying capacitor. Connect a 0.1 µF capacitor between C2P (pin 5) and C2N (pin 6).
6	C2N	passive	Negative terminal of the inverting charge-pump flying capacitor. Paired with C2P (pin 5) via a 0.1 µF capacitor.
7	VN	power_out	Charge-pump generated negative rail, approximately -5.4 V. Bypass to GND with a 0.1 µF capacitor; internally supplies the RS-232 driver's negative swing.
8	R1IN	input	RS-232 line-side receiver input. Accepts ±20 V RS-232 levels; input resistance 3-7 kΩ (typ 5 kΩ). Thresholds: VIL max 0.8 V, VIH min 2.4 V with ~0.5 V hysteresis.
9	R1OUT	output	TTL/CMOS receiver output driven from R1IN. VOL ≤ 0.4 V at IOUT = 1.6 mA; VOH ≥ VCC-0.6 V at IOUT = -1.0 mA. Enters tri-state when XEN is high or during shutdown/XPWRSAVE with no signal at R1IN.
10	XIDLE	output	TTL/CMOS status output that indicates XPWRSAVE / shutdown state. Reports whether an active RS-232 signal is present at R1IN so the host can wake or sleep the driver/charge-pump.
11	T1IN	input	TTL/CMOS driver input to the RS-232 transmitter. Input thresholds VIL max 0.8 V, VIH min 2.4 V (at VCC = 3.3 V) with ~0.5 V hysteresis; leakage ≤ ±1 µA.
12	XPWRSAVE	input	Auto-power-save enable. Driving XPWRSAVE high forces the driver on (normal operation); driving it low arms the XPWRSAVE feature so the internal charge-pump and driver auto-shut when no RS-232 activity is detected on R1IN. XSD must be high for XPWRSAVE to take effect.
13	T1OUT	output	RS-232 line-side driver output. Swings to ±5 V (min) into RL = 3 kΩ from ±5.4 V charge-pump rails; short-circuit current limited to ±60 mA; output resistance 300 Ω with supplies collapsed.
14	GND	power_in	Device ground / return for the charge-pump reservoir capacitors and logic reference.
15	VCC	power_in	Logic and charge-pump supply, +3.0 V to +3.6 V (3.3 V nominal). Bypass to GND with 0.1 µF. Typical ICC 0.5 mA (max 1 mA); XPWRSAVE-idle ICC 1 µA typ, 10 µA max; shutdown ICC 1 µA typ.
16	XSD	input	Shutdown control, active-low. Driving XSD low shuts down the RS-232 driver and the internal charge-pump voltage converter (T1OUT tri-states, VP/VN collapse). Tie to VCC for normal operation.

Key specifications

Parameter	Value
Manufacturer	GEC
Package	TSSOP-16
Category	Comm/UART
Pins	16

Ordering variants

Same part, different packaging or reel option.

WS3221ECYECA
WS3221ECY

CAD (KiCad official)

Symbol: WS3221ECY
Footprint: Package_SO:TSSOP-16_4.4x5mm_P0.65mm
3D model: TSSOP-16 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`ws3221ecy.step`	205 KB	You want the bare part, or you mark your own boards.
`ws3221ecy-etched.step`	2.3 MB	You want the part with `WS3221ECY` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 574 faces against 255 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: GEC datasheet (11 pp, sha256 2b3edbd74b394d18, 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