Transceiver claims to be industry’s smallest isolated RS-485 model
Believed to be the industry’s smallest isolated RS-485 differential bus transceiver, the ISL32704E is designed to provide 4Mbit/s bidirectional data transmission for industrial IoT (IIoT) networks.
The transceiver delivers industry-leading EMI and common-mode transient immunity (CMTI) in a small 4.0 x 5.0mm QSOP package, which is 70 per cent smaller than competitive devices, claims Intersil. It also provides 600VRMS of working voltage, which is claimed to be approximately 50 per cent higher than the closest competitor.
The ISL32704E RS-485 transceiver uses giant magneto-resistance (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. It can be used for the equipment-to-bus interface in IIoT networks that connect programmable logic controllers (PLCs) to instruments, robots, motor drives, data acquisition and digital I/O modules. The GMR isolation offers low radiated emission and low EMI susceptibility compared with other isolation technologies, says the company. 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 also offers 80 per cent less power consumption than competing devices because it does not use power transfer coils or transformers. Its 20mA supply current allows the transceiver to operate in a small QSOP at maximum speed without over-heating. 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 above. The transceiver complies with the EN 50081 and EN 50082-2 EMC standards and the line-voltage standard for information technology equipment (ITE) EN 61000.