Small isolated RS485 transceiver offers breakthrough performance

15-02-2017 | Intersil | Power

Intersil Corporation claimed to have the industry’s smallest isolated RS485 differential bus transceiver designed to provide 4Mbps bidirectional data transmission for Industrial IoT networks. The high-speed ISL32704E delivers industry-leading EMI and CMTI in a small 4mm x 5mm QSOP package that is 70% smaller than competitive devices. It also provides 600VRMS of working voltage, which is approximately 50% higher than the closest competitor. The transceiver leverages 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 device is ideally suited for the equipment-to-bus interface in IIoT networks that connect programmable logic controllers to instruments, robots, motor drives, data acquisition and digital I/O modules. The advantage of their GMR isolation over other isolation technologies is its low radiated emission and low EMI susceptibility. In addition, its GMR isolation does not require the elaborate encoding schemes found in capacitive and transformer-based isolators that use RF carriers or PWM to transfer DC and low frequency signals across the barrier. The device also offers 80% less power consumption than competing devices because it doesn’t use current hungry power transfer coils or transformers. Its 20mA supply current allows it to operate in a tiny QSOP package at maximum speed without overheating. On the non-isolated control-side, the device 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 100 meters and longer distances. The transceiver is fully 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. “Our new ISL32704E isolated RS485 transceiver generates virtually no radiated EMI, solving one of the biggest problems customers experience with their industrial designs,” said Philip Chesley, senior vice president of Precision Products at Intersil. “In addition to not requiring any shielding, this transceiver simplifies PCB layout, uses less board space, and enhances data transmission reliability and integrity.”

By Craig Dyball