Intersil, a subsidiary of Renesas Electronics Corp., has announced two high-speed, isolated RS-485 differential bus transceivers that provide 40 Mbps bidirectional data communication for Industrial Internet of Things (IIoT) networks. The ISL32741E offers 1,000 VRMS working voltage and 6 kV of reinforced isolation, more than 2x higher than competitive solutions. The higher working voltage and reinforced isolation is required for todays most rigorous medical and high-speed motor control applications. The ISL32740E with 2.5 kV of isolation and 600 VRMS working voltage comes in the industrys smallest package, enabling high channel density for programmable logic controllers (PLCs) in factory automation applications.
The ISL3274xE transceivers provide additional advantages over other isolation technologies, including ultra-low radiated emission and EMI susceptibility, support for up to 160 devices on the bus, and an extended 125C temperature range. These devices leverage giant magnetoresistance (GMR) technology that provides galvanic isolation to keep the communication bus free from common-mode noise generated in electrically noisy factory and building automation environments. In addition, Intersils 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 ISL3274xE transceivers are ideally suited for the equipment-to-bus interface in PROFIBUS DP and high-speed RS-485 networks that connect PLCs to instruments, robots, motor control drives, as well as data acquisition and digital I/O modules. In addition to not requiring any shielding, these transceivers simplify PCB layout, use less board space, and enhance data transmission reliability and integrity. The ISL3274xE devices also offer low power consumption. For example, the ISL32740EIAZs 60 mA supply current allows it to operate in a tiny 4 mm by 5 mm QSOP package at maximum speed without overheating.
On the non-isolated control-side, the ISL3274xE transceivers support direct connection to a 3V microcontroller (MCU) 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 ISL3274xE transceivers are 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 latest high-speed RS-485 isolated transceivers radiate virtually no EMI, and they eliminate ground loops between bus nodes to protect data transmission,” said Philip Chesley, vice president of Industrial Analog and Power products at Intersil. “The ISL32741Es high working voltage and ability to push its reinforced isolation barrier up to 6kV enables customers to solve their most difficult IIoT networking design problems.”