The ADM560/ADM561 are four driver/five receiver interface devices designed to meet the EIA-232 standard while operating with a single +3.3 V power supply. The devices feature an on-board dc-to-dc converter, eliminating the need for dual 5 V power supplies. This dc-to-dc converter contains a voltage doubler and voltage inverter, which internally generates 6.6 V from the input +3.3 V power supply. The ADM560 and ADM561 consume only 5 mW making them ideally suited for battery and other power-sensitive applications. A shutdown facility is also provided which reduces the power to 0.66 W.