RS-232 link budget at 250 kbps
The MAX3222CPWR: It handles asynchronous serial links up to 250 kbps — the rate ceiling is set by the driver slew rate and the receiver's 300 mV hysteresis, which together reject cable noise on runs up to a few metres at this speed.
20-TSSOP (4.40 mm width) with 0.65 mm pin pitch — a standard 4-layer board fans out the inner rows without blind vias. The surface-mount footprint matches the TI standard TSSOP-20 land pattern; no exposed pad, so thermal relief is through the leadframe only.