SIT232ESE from SIT, in a SO-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 charge-pump flying capacitor C1 (typ. 1uF to C1-).
2	V+	power_out	Voltage-doubler charge-pump output (approximately +10V no-load). Bypass to GND with a 1uF storage capacitor (C3).
3	C1-	passive	Negative terminal of the voltage-doubler charge-pump flying capacitor C1.
4	C2+	passive	Positive terminal of the inverting charge-pump flying capacitor C2 (typ. 1uF to C2-).
5	C2-	passive	Negative terminal of the inverting charge-pump flying capacitor C2.
6	V-	power_out	Inverting charge-pump output (approximately -10V no-load). Bypass to GND with a 1uF storage capacitor (C4).
7	T2OUT	output	RS-232 level output of transmitter channel 2. Output swing typically ±5V (min) to ±7.3V (typ) into a 3kΩ load; short-circuit current limited to ±60mA max.
8	R2IN	input	RS-232 level input of receiver channel 2. Accepts ±30V, input impedance 3-7 kΩ (typ 5 kΩ). Thresholds: VRIL 0.8V min, VRIH 2.4V max.
9	R2OUT	output	CMOS/TTL logic output of receiver channel 2 (inverting). VOL ≤ 0.4V @ 3.2mA, VOH ≥ 3.5V @ -1mA.
10	T2IN	input	TTL/CMOS logic input to transmitter channel 2. VIL max 0.8V, VIH min 2V, hysteresis 0.3V typ, input current ±10 uA max.
11	T1IN	input	TTL/CMOS logic input to transmitter channel 1. VIL max 0.8V, VIH min 2V, hysteresis 0.3V typ, input current ±10 uA max.
12	R1OUT	output	CMOS/TTL logic output of receiver channel 1 (inverting). VOL ≤ 0.4V @ 3.2mA, VOH ≥ 3.5V @ -1mA.
13	R1IN	input	RS-232 level input of receiver channel 1. Accepts ±30V, input impedance 3-7 kΩ (typ 5 kΩ).
14	T1OUT	output	RS-232 level output of transmitter channel 1. Output swing typically ±5V (min) to ±7.3V (typ) into a 3kΩ load; short-circuit current limited to ±60mA max.
15	GND	power_in	Ground reference for the device. Common return for VCC, V+, V-, and all signal thresholds.
16	VCC	power_in	Positive supply input, 5V ±10% (absolute max 6V). Quiescent supply current 5 mA typ, 10 mA max (no load). Decouple to GND with a 1uF capacitor placed close to the pin.

Key specifications

Parameter	Value
Manufacturer	SIT
Package	SO-16
Category	Interface
Pins	16

Ordering variants

Same part, different packaging or reel option.

SIT232ESE

CAD (KiCad official)

Symbol: SIT232ESE
Footprint: Package_SO:SOIC-16_3.9x9.9mm_P1.27mm
3D model: SO-16 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`sit232ese.step`	217 KB	You want the bare part, or you mark your own boards.
`sit232ese-etched.step`	2.4 MB	You want the part with `SIT232ESE` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 604 faces against 267 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: SIT datasheet (9 pp, sha256 f6cc73b5e7143964, 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