UM232EESE from Union Semiconductor, in a SOP-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 of the voltage-doubler (positive charge pump) flying capacitor. Connect a 0.1μF ceramic capacitor between C1+ (pin 1) and C1- (pin 3).
2	V+	power_out	+2·VCC (approximately +10V) output generated by the internal charge-pump voltage doubler. Bypass to GND with a 0.1μF capacitor; may supply a small load current at the expense of driver swing.
3	C1-	passive	Negative terminal of the voltage-doubler (positive charge pump) flying capacitor. Paired with C1+ (pin 1) via a 0.1μF ceramic capacitor.
4	C2+	passive	Positive terminal of the voltage-inverter (negative charge pump) flying capacitor. Connect a 0.1μF ceramic capacitor between C2+ (pin 4) and C2- (pin 5).
5	C2-	passive	Negative terminal of the voltage-inverter (negative charge pump) flying capacitor. Paired with C2+ (pin 4) via a 0.1μF ceramic capacitor.
6	V-	power_out	-2·VCC (approximately -10V) output generated by the internal charge-pump voltage inverter. Bypass to GND with a 0.1μF capacitor.
7	T2OUT	output	RS-232 line driver #2 output. Inverting driver output swinging typically ±9V (guaranteed ±5V into 3kΩ / 2500pF). Slew rate internally limited to <30V/μs; short-circuit and ±15kV ESD protected.
8	R2IN	input	RS-232 line receiver #2 input. Accepts ±30V input, typical thresholds VIL=1.2V / VIH=1.7V with ~0.5V hysteresis, ~5kΩ internal pull-down to GND. ±15kV ESD protected.
9	R2OUT	output	RS-232 line receiver #2 output (TTL/CMOS logic level). Inverted with respect to R2IN; VOL≤0.4V @ 3.2mA sink, VOH≥3.5V @ 1mA source.
10	T2IN	input	RS-232 line driver #2 input (TTL/CMOS logic level). VIL≤0.8V, VIH≥2.0V; internally pulled to VCC through ~400kΩ so an unconnected input defaults high.
11	T1IN	input	RS-232 line driver #1 input (TTL/CMOS logic level). VIL≤0.8V, VIH≥2.0V; internally pulled to VCC through ~400kΩ so an unconnected input defaults high.
12	R1OUT	output	RS-232 line receiver #1 output (TTL/CMOS logic level). Inverted with respect to R1IN; VOL≤0.4V @ 3.2mA sink, VOH≥3.5V @ 1mA source.
13	R1IN	input	RS-232 line receiver #1 input. Accepts ±30V input, typical thresholds VIL=1.2V / VIH=1.7V with ~0.5V hysteresis, ~5kΩ internal pull-down to GND. ±15kV ESD protected.
14	T1OUT	output	RS-232 line driver #1 output. Inverting driver output swinging typically ±9V (guaranteed ±5V into 3kΩ / 2500pF). Slew rate internally limited to <30V/μs; short-circuit and ±15kV ESD protected.
15	GND	power_in	Ground / 0V reference for logic and RS-232 signaling.
16	VCC	power_in	Positive supply input, +4.5V to +5.5V (nominal +5V). Typical ICC = 10mA (15mA max) no-load. Bypass to GND with at least 0.1μF ceramic.

Key specifications

Parameter	Value
Manufacturer	Union Semiconductor
Package	SOP-16
Category	Interface
Pins	16

Ordering variants

Same part, different packaging or reel option.

UM232EESE
UM232EESEPE
UM232EESEUE

CAD (KiCad official)

Symbol: UM232EESE
Footprint: Package_SO:SOIC-16_3.9x9.9mm_P1.27mm
3D model: SOP-16 (KiCad packages3D, STEP)

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: Union Semiconductor datasheet (None pp, sha256 839dd4779cce1a1e, 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