the max232 device is a dual driver/receiver that includes a capacitive voltage generator to supply tia/eia-232-232-f voltage levels from a single 5-v supply. each receiver converts tia/eia-232-f inputs to 5-v ttl/cmos levels. these receivers have a typical threshold of 1.3 v a typical hysteresis of 0.5 v and can accept 30-v inputs. each driver converts ttl/cmos input levels into tia/eia-232-f levels. the driver receiver and voltage-generator functions are available as cells in the texas instruments linasic library.