Active production with 5 kVrms galvanic barrier
The MAX14949EWE+: The 5000 Vrms isolation rating means this device provides a reinforced galvanic barrier between the bus-side transceiver and the logic-side UART. In a 24 V fieldbus network with long cable runs, that barrier protects the host controller from ground potential differences that can exceed 1 kV during a lightning surge or a phase-to-ground fault.
500 kbps data rate and 35 kV/µs CMTI
The 500 kbps data rate covers the majority of RS-485 industrial segments — Modbus RTU at 115.2 kbps, Profibus DP at 12 Mbps is out of reach, but CANopen-style fieldbuses and most PLC-to-I/O links fit comfortably. The unidirectional channel arrangement (2 inputs on side 1, 1 input on side 2) maps directly to a half-duplex RS-485 bus: one channel for TX data, one for RX data, and the third for a direction-control signal like DE/RE on the transceiver. Every IGBT switching event couples a fast-rising common-mode voltage across the isolation barrier — if the CMTI is too low, the output side sees a false edge and corrupts the data frame. 35 kV/µs is enough to reject the transients from a 10 kHz PWM inverter with a 100 ns rise time.
Capacitive coupling and supply flexibility
Capacitive coupling technology gives this isolator a lower power draw and longer operational life than an optocoupler-based alternative — no LED ageing, no CTR degradation over temperature. The creepage distance across the wide-body package meets the 8 mm minimum required for 5 kVrms reinforced isolation per IEC 60950-1.
Industrial temperature and compliance
ROHS3 compliance (EU 2015/863) means no restricted substances above the threshold limits, and no exemption expiry to track.