These are circuits taken directly from the Maxim application notes. Give them the credit and hassle. Pinouts: DIP/SO LCC MAX202E/MAX232E MAX232E V C N V G C1+ 1 /--__--. 16 Vcc + 1 C c N V+ 2 | | 15 GND + c D C1- 3 | | 14 T1OUT C2+ 4 | | 13 R1IN 3 2 1 20 19 C2- 5 | | 12 R1OUT C1- 4 18 T1OUT V- 6 | | 11 T1IN T2OUT 7 | | 10 T2IN C2+ 5 17 R1IN R2IN 8 | | 09 R2OUT -------- NC 6 16 NC C2- 7 15 R1OUT V- 8 14 T1IN 9 10 11 12 13 T R N R T 2 2 C 2 2 O I O I U N U N T T The pin numbers in the circuit below refer to the DIP/SO package. With the DIP/SO package, the capacitors are 0.1 micro-farads. With the LCC package, the capacitors are 1.0 micro-farads. +5V IN Pin 6----)|----GND Pin 15----GND | | +----|(--GND Pin 1----|(----Pin 3 | 6.3V +----Pin 16 | Pin 4----|(----Pin 5 +----)|----Pin 2 16V 6.3V TTL In Pin 11 --------> RS-232 Out Pin 14 TTL In Pin 10 --------> RS-232 Out Pin 7 TTL Out Pin 12 <-------- RS-232 In Pin 13 TTL Out Pin 9 <-------- RS-232 In Pin 8 Call Maxim 800-998-8800 for free samples or literature. Maxim Integrated Products 120 San Gabriel Drive Sunnyvale, CA 94086 USA (1) 408-737-7600 http://www.maxim-ic.com