MAX232 Pinout

MAX232 RS-232 Transceiver · TTL↔RS-232 level shifter with built-in charge pump; single 5V supply (plus 4 capacitors).

DIP-16 Interface 16 pins No backend · 100% client-side

C1+ 1

V+ 2

C1− 3

C2+ 4

C2− 5

V− 6

T2OUT 7

R2IN 8

MAX232 DIP-16

16 VCC

15 GND

14 T1OUT

13 R1IN

12 R1OUT

11 T1IN

10 T2IN

9 R2OUT

PowerGNDInputOutputI/OControl

Pin	Name	Type	Function
1	C1+	Control	Charge-pump capacitor 1 positive
2	V+	Output	Charge-pump boosted output (about +8.5V; cap to ground)
3	C1−	Control	Charge-pump capacitor 1 negative
4	C2+	Control	Charge-pump capacitor 2 positive
5	C2−	Control	Charge-pump capacitor 2 negative
6	V−	Output	Charge-pump negative output (about −8.5V)
7	T2OUT	Output	Transmitter 2 RS-232 output
8	R2IN	Input	Receiver 2 RS-232 input
9	R2OUT	Output	Receiver 2 TTL output
10	T2IN	Input	Transmitter 2 TTL input
11	T1IN	Input	Transmitter 1 TTL input
12	R1OUT	Output	Receiver 1 TTL output
13	R1IN	Input	Receiver 1 RS-232 input
14	T1OUT	Output	Transmitter 1 RS-232 output
15	GND	GND	Ground
16	VCC	Power	Supply +5V

How to · reading it

How to read the MAX232 pinout

01
Find pin 1
One end of the chip has a half-circle notch or a dot; with the notch facing up, the top-left pin is pin 1.
02
Count counter-clockwise
Count counter-clockwise from pin 1: go down the left side first, then up the right side from the bottom.
03
Check the table below
Look up each pin's function by number in the table below; power/ground are color-coded, and alternate-function signals are in parentheses.

FAQ

Which external capacitors are needed?

Classically 4 capacitors (C1+/C1−, C2+/C2−, V+, V−), 1µF on the original; the MAX232A can use 0.1µF. Plus a VCC decoupling capacitor.

How do I connect the TTL side to a microcontroller?

T1IN/T2IN connect to the MCU's TX, R1OUT/R2OUT to the MCU's RX; the T1OUT/R1IN side connects to the DB9 RS-232 lines.

Can it convert 3.3V levels?

The MAX232 is a 5V part; for 3.3V systems use the MAX3232 (pin-compatible, 3–5.5V supply).

Data source

Pinout data comes from TI MAX232 datasheet (standard DIP-16 numbering). Refer to the actual device datasheet as authoritative for the pinout.