The hin232? is +5V Powered RS-232 Transmitters/Receivers

The HIN232-HIN241 family of RS-232 transmitters/receivers
interface circuits meet all ElA RS-232E and V.28 specifications,
and are particularly suited for those applications where ±12V is
not available. They require a single +5V power supply (except
HIN239) and feature onboard charge pump voltage converters
which generate +10V and -10V supplies from the 5V supply.
The family of devices offer a wide variety of RS-232
transmitter/receiver combinations to accommodate various
applications (see Selection Table).
The drivers feature true TTL/CMOS input compatibility, slewrate-
limited output, and 300Ω power-off source impedance.
The receivers can handle up to ±30V, and have a 3kΩ to 7kΩ
input impedance. The receivers also feature hysteresis to
greatly improve noise rejection.