ST3232BTR from STMicroelectronics, 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	C1+	passive	Positive terminal for the first charge pump capacitor (C1). Connects to the external flying capacitor used by the voltage-doubler charge pump.
2	V+	power_out	Doubled voltage terminal, output of the internal charge pump (approximately +2xVCC). Requires an external reservoir capacitor (C3) to GND. Absolute max (VCC - 0.3) to 7 V.
3	C1-	passive	Negative terminal for the first charge pump capacitor (C1). Connects to the external flying capacitor used by the voltage-doubler charge pump.
4	C2+	passive	Positive terminal for the second charge pump capacitor (C2). Connects to the external flying capacitor used by the voltage-inverter charge pump.
5	C2-	passive	Negative terminal for the second charge pump capacitor (C2). Connects to the external flying capacitor used by the voltage-inverter charge pump.
6	V-	power_out	Inverted voltage terminal, output of the internal charge pump (approximately -VCC to -2xVCC). Requires an external reservoir capacitor (C4) to GND. Absolute max 0.3 to -7 V.
7	T2OUT	output	Second transmitter (driver) RS-232 output. Delivers ±5 V typical swing into a 3 kΩ load; short-circuit current limited to ±60 mA.
8	R2IN	input	Second receiver RS-232 input. Accepts ±25 V input range with typical 5 kΩ input resistance; thresholds compliant with EIA/TIA-232.
9	R2OUT	output	Second receiver TTL/CMOS output. Drives VOL ≤ 0.4 V at 1.6 mA and VOH ≥ VCC-0.6 V at -1 mA; inverting relative to R2IN.
10	T2IN	input	Second transmitter (driver) TTL/CMOS input. Logic thresholds VTIL ≤ 0.8 V, VTIH ≥ 2 V (VCC = 3.3 V) with ~250 mV hysteresis; drives T2OUT (inverting).
11	T1IN	input	First transmitter (driver) TTL/CMOS input. Logic thresholds VTIL ≤ 0.8 V, VTIH ≥ 2 V (VCC = 3.3 V) with ~250 mV hysteresis; drives T1OUT (inverting).
12	R1OUT	output	First receiver TTL/CMOS output. Drives VOL ≤ 0.4 V at 1.6 mA and VOH ≥ VCC-0.6 V at -1 mA; inverting relative to R1IN.
13	R1IN	input	First receiver RS-232 input. Accepts ±25 V input range with typical 5 kΩ input resistance; thresholds compliant with EIA/TIA-232.
14	T1OUT	output	First transmitter (driver) RS-232 output. Delivers ±5 V typical swing into a 3 kΩ load; short-circuit current limited to ±60 mA.
15	GND	power_in	Ground reference for the device.
16	VCC	power_in	Supply voltage input, 3.0 to 5.5 V operating range (absolute max -0.3 to 6 V). Typical ISUPPLY 0.3 mA (VCC = 3.3 V) / 1 mA (VCC = 5 V). Bypass with a 0.1 µF capacitor to GND.

Key specifications

Parameter	Value
Manufacturer	STMicroelectronics
Package	TSSOP-16
Category	Interface
Pins	16

Ordering variants

Same part, different packaging or reel option.

ST3232BTRCTR
ST3232BTR
ST3232BTRCDR
ST3232BTRBDR
ST3232BTRCWR
ST3232BTRBWR

CAD (KiCad official)

Symbol: ST3232BTR
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
`st3232btr.step`	205 KB	You want the bare part, or you mark your own boards.
`st3232btr-etched.step`	2.6 MB	You want the part with `ST3232BTR` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 637 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: STMicroelectronics datasheet (18 pp, sha256 38bf6fa5becf1b1f, retrieved 2026-08-17, tier: manufacturer)
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