Datasheet

Data Sheet ADM202
Rev. B | Page 7 of 10
THEORY OF OPERATION
The ADM202 is an RS-232 driver/receiver designed to solve
interface problems by meeting the TIA/EIA-232E specifications
while using a single digital 5 V supply. The EIA standard
requires that transmitters deliver ±5 V minimum on the
transmission channel and that receivers can accept signal levels
down to ±3 V. The device achieves this by integrating step-up
voltage converters and level shifting transmitters and receivers
on the same chip. CMOS technology keeps the power dissipation
to an absolute minimum.
The ADM202 contains an internal voltage doubler and a voltage
inverter that generates ±10 V from the 5 V input. External
0.1 μF capacitors are required for the internal voltage converter.