The MAX206CNG is an RS-232 transceiver from Analog Devices Inc. It features a 4/3 driver/receiver configuration and operates at data rates up to 120Kbps.
The MAX206ENG is an RS232 transceiver from Analog Devices / Maxim Integrated. It operates on a single 4.5V to 5.5V supply and supports data rates up to 120Kbps.