RS485 isolator with 5000 Vrms — what it means on the bus
The MAX14941GWE+ from Maxim Integrated is a 3-channel digital isolator with an integrated RS485 transceiver, built on capacitive coupling technology. It delivers 5000 Vrms galvanic isolation between the logic-side and bus-side circuits, which is the rating that decides fit for any application where ground potential differences or safety isolation are required — think motor drives, solar inverters, or medical patient-interface equipment. The 20 Mbps data rate supports high-speed fieldbus links like PROFIBUS or Modbus RTU at extended baud rates, while the unidirectional channel arrangement (2 inputs on side 1, 1 input on side 2) matches the typical half-duplex RS485 topology: one channel for transmit, one for receive, and a third for a control signal like driver enable. Supply voltage is 1.71 V to 5.5 V on the logic side and 4.5 V to 5.5 V on the bus side.
5000 Vrms and 35 kV/µs CMTI — the noise-floor gate
Isolation voltage is 5000 Vrms. Common-mode transient immunity is 35 kV/µs. Propagation delay is 68 ns max in both directions, which is tight enough for 20 Mbps signaling without bit-rate margin issues on short cable runs. The 15 ns rise/fall time keeps the signal edges clean enough for bus lengths up to a few hundred meters at 20 Mbps, though longer runs may need a slower data rate to manage reflections.