ST3232CDR from STMicroelectronics, in a SOIC-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. Connect C1 (typ. 0.1 µF at 3 V, 0.047 µF at 5 V) between C1+ and C1-.
2	V+	power_out	Doubled (positive) voltage terminal generated by the charge pump (approx. +2 x VCC). Requires reservoir capacitor C3 (typ. 0.1 µF at 3 V, 0.33 µF at 5 V) to GND.
3	C1-	passive	Negative terminal for the first charge pump capacitor. Connect C1 between C1+ (pin 1) and C1- (pin 3).
4	C2+	passive	Positive terminal for the second charge pump capacitor. Connect C2 (typ. 0.1 µF at 3 V, 0.33 µF at 5 V) between C2+ and C2-.
5	C2-	passive	Negative terminal for the second charge pump capacitor. Connect C2 between C2+ (pin 4) and C2- (pin 5).
6	V-	power_out	Inverted (negative) voltage terminal generated by the charge pump inverter (approx. -2 x VCC). Requires reservoir capacitor C4 (typ. 0.1 µF at 3 V, 0.33 µF at 5 V) to GND. Absolute max 0.3 to -7 V.
7	T2OUT	output	Second transmitter (driver) RS-232 output. Output voltage swing typ. +/-5.4 V into 3 kOhm load; short-circuit current +/-60 mA max.
8	R2IN	input	Second receiver RS-232 input. Operating input range +/-25 V; input resistance 3-7 kOhm (typ. 5 kOhm); thresholds VRIL 0.6-1.5 V, VRIH up to 2.4 V.
9	R2OUT	output	Second receiver TTL/CMOS output. VOL <= 0.4 V at IOUT = 1.6 mA; VOH >= VCC-0.6 V at IOUT = -1 mA.
10	T2IN	input	Second transmitter (driver) TTL/CMOS input. VIL <= 0.8 V, VIH >= 2 V (VCC = 3.3 V) or 2.4 V (VCC = 5 V); typical input hysteresis 250 mV.
11	T1IN	input	First transmitter (driver) TTL/CMOS input. VIL <= 0.8 V, VIH >= 2 V (VCC = 3.3 V) or 2.4 V (VCC = 5 V); typical input hysteresis 250 mV.
12	R1OUT	output	First receiver TTL/CMOS output. VOL <= 0.4 V at IOUT = 1.6 mA; VOH >= VCC-0.6 V at IOUT = -1 mA.
13	R1IN	input	First receiver RS-232 input. Operating input range +/-25 V; input resistance 3-7 kOhm (typ. 5 kOhm); thresholds VRIL 0.6-1.5 V, VRIH up to 2.4 V.
14	T1OUT	output	First transmitter (driver) RS-232 output. Output voltage swing typ. +/-5.4 V into 3 kOhm load; short-circuit current +/-60 mA max.
15	GND	power_in	Ground reference for all supply, logic and RS-232 signals.
16	VCC	power_in	Positive supply voltage, 3.0 to 5.5 V operating (absolute max -0.3 to 6 V). Supply current typ. 0.3 mA at 3 V, 1 mA at 5 V (no load). Decouple with Cbypass to GND (0.1 µF at 3 V, 0.33 µF at 5 V).

Key specifications

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

Ordering variants

Same part, different packaging or reel option.

ST3232CDR
ST3232BDR
ST3232CWR
ST3232BWR
ST3232CTR
ST3232BTR

CAD (KiCad official)

Symbol: ST3232CDR
Footprint: Package_SO:SOIC-16_3.9x9.9mm_P1.27mm
3D model: SOIC-16 (KiCad packages3D, STEP)

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