Dual EIA/TIA-232 (RS-232) driver/receiver with an on-chip capacitive charge-pump voltage generator, in a SOIC-16 package. It produces the bipolar +/- line levels RS-232 needs from a single 5 V supply, so a UART's TTL TX/RX can talk to a legacy serial port. Two drivers and two receivers, with four external charge-pump capacitors. The classic TTL-to-RS-232 level shifter.

Pinout

Pin	Name	Type	Function
1	C1+	passive	Positive lead of the C1 charge-pump flying capacitor (typ. 1µF). Connect to C1- (pin 3) through the external capacitor. Part of the voltage-doubler stage that generates VS+.
2	VS+	power_out	Positive charge-pump output for the reservoir storage capacitor only. Nominally +8 to +10 V above GND, sourced through the C1 doubler. Bypass to GND with a 1µF capacitor; do not use as an external supply rail.
3	C1-	passive	Negative lead of the C1 charge-pump flying capacitor (typ. 1µF). Pairs with C1+ (pin 1) via the external capacitor to form the +5V→+10V doubler.
4	C2+	passive	Positive lead of the C2 charge-pump flying capacitor (typ. 1µF). Connect to C2- (pin 5) through the external capacitor. Part of the inverter stage that generates VS−.
5	C2-	passive	Negative lead of the C2 charge-pump flying capacitor (typ. 1µF). Pairs with C2+ (pin 4) via the external capacitor to form the +10V→−10V inverter.
6	VS-	power_out	Negative charge-pump output for the reservoir storage capacitor only. Nominally −8 to −10 V below GND, generated by the C2 inverter stage. Bypass to GND with a 1µF capacitor; do not use as an external supply rail.
7	T2OUT	output	Driver-2 RS-232 line output to the remote RS-232 system. Swings between VS− and VS+ (typ. ±7V into a 3kΩ load), meeting TIA/EIA-232-F line levels. Short-circuit protected.
8	R2IN	input	Receiver-2 RS-232 line input from the remote RS-232 system. Accepts ±30V, typical input resistance 5 kΩ (3–7 kΩ), switching thresholds 1.2V (typ.) with 0.5V hysteresis.
9	R2OUT	output	Receiver-2 logic (TTL/CMOS) output to the local UART. VOH ≥ 3.5V at IOH = −1 mA; VOL ≤ 0.4V at IOL = 3.2 mA.
10	T2IN	input	Driver-2 logic (TTL/CMOS) data input from the local UART. VIH ≥ 2V, VIL ≤ 0.8V referenced to VCC = 5V.
11	T1IN	input	Driver-1 logic (TTL/CMOS) data input from the local UART. VIH ≥ 2V, VIL ≤ 0.8V referenced to VCC = 5V.
12	R1OUT	output	Receiver-1 logic (TTL/CMOS) output to the local UART. VOH ≥ 3.5V at IOH = −1 mA; VOL ≤ 0.4V at IOL = 3.2 mA.
13	R1IN	input	Receiver-1 RS-232 line input from the remote RS-232 system. Accepts ±30V, typical input resistance 5 kΩ (3–7 kΩ), switching thresholds 1.2V (typ.) with 0.5V hysteresis.
14	T1OUT	output	Driver-1 RS-232 line output to the remote RS-232 system. Swings between VS− and VS+ (typ. ±7V into a 3kΩ load), meeting TIA/EIA-232-F line levels. Short-circuit protected.
15	GND	power_in	Device ground / 0V reference for all supply rails and signal levels.
16	VCC	power_in	Positive supply voltage. Recommended 4.5–5.5V (nom. 5V); absolute max 6V. Typical supply current ICC = 8 mA with all outputs open. Decouple to GND close to the pin.

Key specifications

Parameter	Value
Type	Dual RS-232 driver/receiver
Supply voltage	5 V (single)
Line levels	Bipolar ± via charge pump
Channels	2 drivers + 2 receivers
External caps	4 (1 µF; 0.1 µF for MAX232A)
Standard	TIA/EIA-232-F
Package	SOIC-16
Body (L×W×H)	9.9 × 3.9 × 1.75 mm

Ordering variants

Same part, different packaging or reel option.

MAX232D (SOIC-16, tube)
MAX232DR (SOIC-16, tape & reel)

CAD (KiCad official)

Symbol: Interface_UART:MAX232
Footprint: Package_SO:SOIC-16_3.9x9.9mm_P1.27mm
3D model: SOIC-16 (KiCad packages3D)

Provenance

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

Datasheet: Texas Instruments datasheet (27 pp, sha256 47d45fefa0db5981, retrieved 2026-08-17, tier: manufacturer)
Extractor: ds2sf (Claude) — every pin and dimension is cited to a datasheet page; refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF