Rugged RS-485 transceivers for IIoT networks
These new high-speed, isolated RS-485 differential bus transceivers provide 40Mbps 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 alternative products. The higher working voltage and reinforced isolation is required for rigorous medical and high-speed motor control applications. The ISL32740E with 2.5 kV of isolation and 600 VRMS working voltage comes in the industry’s 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 125°C temperature range. These devices employ 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. Intersil’s 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 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 ISL32740EIAZ’s 60 mA supply current allows it to operate in a 4 x 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 while the isolated bus-side connects to a higher voltage 5V supply for communication of strong bus signals across 100m 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.
The transceivers are priced from $3.79 to $4.79 depending on package type and temperature range. Evaluation boards are available for $99.
next page; feature list…
Key Features and Specifications of ISL32741E and ISL32740E Family
• 40 Mbps data rate enables high-speed data transmission
• Supports 3V to 5V power supplies
• Offers 5 nsec pulse skew and 20 nsec propagation delay
• The ISL32741E offers 6 kVRMS isolation/1,000 VRMS working voltage, and 12.8 kV surge immunity
• The ISL32740E offers 2.5 kVRMS isolation/600 VRMS working voltage
• Single unit load allows up to 160 devices on the bus
• 50 kV/µsec (typ), 30 kV/µsec (min) common-mode transient immunity provides reliable data transmission in noisy environments
• Offers a barrier lifetime of 44,000 years
• 15 kV ESD bus-pin protection, and low EMC footprint
• Thermal shutdown protection prevents damage during bus contention, or excessive current
• PROFIBUS compliant