MAX232 Reference Tables, Pins & Specifications

Selected packagePDIP-16MAX232N

Physical connections16 pinsPackage-specific numbering

Reference collection2 tables14 parameters & pin functions

Pin reference

Signal names, electrical functions and connection guidance

PDIP-16

Physical pin numbers16 pins

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MAX232 pin functions and connections
Signal	Type	Function & connection
C1+	Capacitor	Positive connection of the flying capacitor C1. Connection guidance Connect C1 (1 µF) between pins 1 and 3; positive terminal to pin 1 if polarized. Use 1 µF flying capacitors for this MAX232. Ceramic capacitors avoid polarity concerns; follow the marked +/− connections for polarized parts.
VS+	Output	Positive voltage reservoir of the internal charge pump. Connection guidance Connect the positive reservoir capacitor as shown in the manufacturer’s typical application. This is not a general-purpose supply. Positive charge-pump reservoir. Use it for the reservoir capacitor, not as an external power output.
C1−	Capacitor	Negative connection of the flying capacitor C1. Connection guidance Connect to the other side of C1 at pin 1. Use 1 µF flying capacitors for this MAX232. Ceramic capacitors avoid polarity concerns; follow the marked +/− connections for polarized parts.
C2+	Capacitor	Positive connection of the inverting capacitor C2. Connection guidance Connect C2 (1 µF) between pins 4 and 5; positive terminal to pin 4 if polarized. Use 1 µF flying capacitors for this MAX232. Ceramic capacitors avoid polarity concerns; follow the marked +/− connections for polarized parts.
C2−	Capacitor	Negative connection of the inverting capacitor C2. Connection guidance Connect to the other side of C2 at pin 4. Use 1 µF flying capacitors for this MAX232. Ceramic capacitors avoid polarity concerns; follow the marked +/− connections for polarized parts.
VS−	Output	Negative voltage reservoir of the internal charge pump. Connection guidance Connect the negative reservoir capacitor to ground; observe capacitor polarity. Not a general-purpose supply. Negative charge-pump reservoir. For a polarized reservoir capacitor, the positive terminal goes to ground.
T2OUT	Output	Channel 2 transmit output at RS-232 voltage levels. Connection guidance Connect to the remote receiver. Inverts the logic applied to T2IN (pin 10). Bipolar RS-232 output. Typical levels are about ±7 V at 5 V supply, 25 °C and a 3 kΩ load. Keep it off microcontroller GPIO inputs.
R2IN	Input	Channel 2 receive input from an RS-232 line. Connection guidance Connect to the remote transmitter. Its converted logic appears at R2OUT (pin 9). RS-232 input only; specified input range is −30 to +30 V. The paired logic output is inverted.
R2OUT	Output	Channel 2 receive output at TTL/CMOS logic levels. Connection guidance Connect to the local UART receive input; paired with R2IN (pin 8). Logic-level output for the local UART. A negative RS-232 input produces HIGH; a positive input produces LOW.
T2IN	Input	Channel 2 transmit input from TTL/CMOS logic. Connection guidance Connect to the local UART transmit output; paired with T2OUT (pin 7). LOW: 0.8 V or below. HIGH: 2 V or above. The paired RS-232 output is inverted; do not apply RS-232 voltage to this logic input.
T1IN	Input	Channel 1 transmit input from TTL/CMOS logic. Connection guidance Connect to the local UART transmit output; paired with T1OUT (pin 14). LOW: 0.8 V or below. HIGH: 2 V or above. The paired RS-232 output is inverted; do not apply RS-232 voltage to this logic input.
R1OUT	Output	Channel 1 receive output at TTL/CMOS logic levels. Connection guidance Connect to the local UART receive input; paired with R1IN (pin 13). Logic-level output for the local UART. A negative RS-232 input produces HIGH; a positive input produces LOW.
R1IN	Input	Channel 1 receive input from an RS-232 line. Connection guidance Connect to the remote transmitter; paired with R1OUT (pin 12). RS-232 input only; specified input range is −30 to +30 V. The paired logic output is inverted.
T1OUT	Output	Channel 1 transmit output at RS-232 voltage levels. Connection guidance Connect to the remote receiver. Inverts the logic applied to T1IN (pin 11). Bipolar RS-232 output. Typical levels are about ±7 V at 5 V supply, 25 °C and a 3 kΩ load. Keep it off microcontroller GPIO inputs.
GND	Ground	Common ground reference for logic and the transceiver. Connection guidance Connect to circuit ground and the serial connector’s signal ground. 0 V reference. Connect the local logic ground and the remote interface’s signal ground.
VCC	Supply	Positive supply input: 5 V nominal. Connection guidance Use a regulated 4.5–5.5 V supply. Place the supply bypass capacitor close to VCC and GND. 5 V nominal; keep the supply within 4.5–5.5 V. Use a common supply with the connected logic circuit.

Electrical & physical specifications

Texas Instruments MAX232N · PDIP-16 · Reference values

Manufacturer-referenced values14 parameters

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Parameter	Value	Conditions / notes
Supply voltage	4.5–5.5 V	5 V nominal; recommended operating range
Maximum data rate	120 kbit/s	One transmitter output switching; see datasheet test conditions
Transmit / receive channels	2 / 2	Two drivers and two receivers
Supply current	8 mA typ. / 10 mA max.	VCC = 5.5 V, outputs open, ambient = 25 °C
Driver output	+7 V / −7 V typical	VCC = 5 V, ambient = 25 °C, 3 kΩ load to GND; +5 V / −5 V guaranteed limits
Logic input HIGH / LOW	≥ 2 V / ≤ 0.8 V	T1IN and T2IN; values between thresholds are undefined
Receiver input range	−30 to +30 V	R1IN and R2IN only
Receiver hysteresis	0.5 V typical	At VCC = 5 V
Operating temperature	0 to +70 °C	MAX232N commercial grade; MAX232I has a different range
Charge-pump capacitors	4 × 1 µF	Plus supply bypass; follow the typical application, section 8
Package	PDIP-16, 16 leads	TI N package; 2.54 mm lead pitch
Junction-to-ambient	60.6 °C/W	PDIP-16; datasheet thermal characterization conditions
Supply absolute maximum	−0.3 to +6 V	Stress rating only, not an operating range
Maximum junction temperature	150 °C	Absolute maximum, not the ambient operating rating

Reference: TI SLLS047N, sections 4–8 and package drawings. Check the exact manufacturer and suffix before substituting MAX232A, MAX3232 or another family member. Verify a production footprint against your ordered part.