Half-duplex RS-485/422 transceiver — 5V bus interface
The SN75176BPSG4: It operates from a 4.75V to 5.25V supply and includes 50 mV of receiver hysteresis for noise immunity on differential buses.
5V-only supply — 3.3V logic compatibility
The supply range is 4.75V to 5.25V, meaning the part is not specified for 3.3V operation. Driving the VCC pin below 4.75V may cause undefined behavior; the receiver and driver thresholds are referenced to a 5V rail. If the design uses a 3.3V microcontroller UART, level translation or a 3.3V-rated RS-485 transceiver is needed.
