[ADM2867E/ADM2865E/ADM2863E/ADM2861E] RS-485/422 с кучей фич и DC-DC 5V 90 мА. $14 розница, $9.63 @ 400 * High common-mode transient immunity: 250 kV/µs
* Short-circuit, open-circuit, and floating inputreceiverfail-safe
* Supports 196 bus nodes (72 kΩ receiver input impedance)
* Full hot swap support (glitch free power-up/power-down)
* Correct reversed cable connection on A, B, Y, and Z bus
pins while maintaining full receiver fail-safe feature
adm2867e_adm2865e_adm2863e_adm2861e.pdf
Цена ипанутая, но фичастый, это не отнять.