9.2.1 Design Requirements

Example Application: Isolated Bus Node with Transient Protection

• RS-485-compliant bus interface (needs differential signal amplitude of at least 1.5 V under fully-loaded conditions – essentially, maximum number of nodes connected and with dual 120-Ω termination).
• Galvanic isolation of both signal and power supply lines.
• Able to withstand ESD transients up to 12 kV (per IEC 61000-4-2) and EFTs up to 4 kV (per IEC 61000-4-4).
• • Full control of data flow on bus in order to prevent contention (for half-duplex communication).