Intersil has introduced the isolated RS-485 differential bus transceiver deliberate to supply 4Mbps bidirectional data transmission for IoT networks. The ISL32704E delivers electromagnetic interference (EMI) and common-mode transient immunity (CMTI) in a 4mm x 5mm QSOP package. It also provides 600VRMS of working voltage.

The ISL32704E RS-485 transceiver leverages giant magnetoresistance (GMR) technology to provide galvanic isolation that keeps the communication bus free from common-mode noise generated in electrically noisy factory and building automation environments. The ISL32704E is preferably suited for the equipment-to-bus interface in industrial IoT networks that connect programmable logic controllers (PLCs) to instruments, robots, motor drives, data acquisition and digital I/O modules. Its GMR isolation does not require the elaborate encoding schemes found in capacitive and transformer-based isolators that use RF carriers or pulse-width modulation (PWM) to transfer DC and low frequency signals across the barrier.

The ISL32704E offer 80% less power consumption in not using current hungry power transfer coils or transformers. Its 20mA supply current allows the ISL32704E to operate in a QSOP package at maximum speed without overheating. On the non-isolated control-side, the ISL32704E supports direct connection to a 3V microcontroller while the isolated bus-side connects to a higher voltage 5V supply for communication of strong bus signals across 100m and longer distances. The ISL32704E is compliant with the EN 50081 and EN 50082-2 electromagnetic compatibility (EMC) standards and the umbrella line-voltage standard for information technology equipment (ITE) EN 61000.