The MAX232 is an RS-232 line driver/receiver that converts TTL/CMOS logic levels to RS-232 voltage levels (+/-12V) using charge-pump capacitors. Used to interface microcontrollers with RS-232 serial ports.
| Pin | Name | Function | Type |
|---|---|---|---|
| 1 | C1+ | Charge pump capacitor 1 positive | I/O |
| 2 | VS+ | Charge pump positive output ~+10V | PWR |
| 3 | C1- | Charge pump capacitor 1 negative | I/O |
| 4 | C2+ | Charge pump capacitor 2 positive | I/O |
| 5 | C2- | Charge pump capacitor 2 negative | I/O |
| 6 | VS- | Charge pump negative output ~-10V | PWR |
| 7 | T2OUT | RS-232 TX2 output | BUS |
| 8 | R2IN | RS-232 RX2 input | BUS |
| 9 | R2OUT | TTL RX2 output to MCU | BUS |
| 10 | T2IN | TTL TX2 input from MCU | BUS |
| 11 | T1IN | TTL TX1 input from MCU | BUS |
| 12 | R1OUT | TTL RX1 output to MCU | BUS |
| 13 | R1IN | RS-232 RX1 input | BUS |
| 14 | T1OUT | RS-232 TX1 output | BUS |
| 15 | GND | Ground | GND |
| 16 | VCC | +5V supply | PWR |