About the real-life application of Silicon Labs’ new isolation smart switch

Silicon Labs has launched a series of compact, reliable isolation smart switches that can drive any load, even in the harshest industrial environments. The new Si834x isolation switches are ideal for driving resistive and inductive loads such as solenoid valves, relays and lights in industrial control systems, including programmable logic controllers (PLCs), I/O modules, relay drivers and servo motor controllers wait. Each isolation switch is electrically isolated for safety, using Silicon Labs' breakthrough CMOS-based isolation technology to deliver greater reliability and performance compared to traditional optocoupler-based isolation, including High common-mode transient immunity (CMTI) exceeding 100kV/μs.

The Si834x isolation switch family supports high-side and low-side switching options, low on-resistance (145 mΩ RON), up to 700mA continuous current per IEC 61131-2 standard, comprehensive protection and diagnostic reporting, and use in industrial automation systems advanced configuration, monitoring and control. The switching logic interface can be as simple as four low-power CMOS digital inputs or as rich and flexible as a full serial peripheral interface (SPI) that can control up to 128 channels through 4 MCU pins.

Brian Mirkin, vice president and general manager of power products at Silicon Labs, said: "The new Si834x isolation smart switch family embodies Silicon Labs' third generation of industrial automation isolation innovation. The Si834x family expands our broad isolator product portfolio by integrating with our PLC inputs. The combination of isolator and isolation FET driver provides a complete solution. The Si834x isolation switch has a fully integrated 24V digital output solution with best-in-class switch protection, flexible configuration and comprehensive diagnostic feedback, which is better than opto-coupled isolators, Power FETs and other competing options.”

Advanced switch and load monitoring technology combined with fast response to changing conditions make the Si834x isolation switches a very powerful and flexible solution for driving a variety of loads. Each isolation switch detects open circuit conditions and protects against overcurrent, overvoltage due to demagnetization (induced surge or flyback voltage) and overtemperature conditions. The innovative multi-voltage smart clamp effectively handles unlimited demagnetization energy. Overcurrent protection, including an inrush current mode not found on competing devices, allows the switch to drive challenging loads.

The Si834x isolation switch achieves better inductive load driving performance and safer overload protection than competing products. By using innovative fast switching impedance and clamping voltage control, it eliminates the common low efficiency, loss of life reliability, and loss of life reliability of competing products. Complex cooling solutions. While other solutions may shut down when entering a fault state, the Si834x isolation switch can continue to operate in a restricted but functional state with reduced channel performance, significantly improving system uptime.

The isolating switches feature a mature logic interface and eight independent diagnostic reports, providing unprecedented detailed status and control for each switch, making the Si834x devices the most flexible switches on the market. Diagnostics can be configured, monitored and cleared via SPI, or output to an active-low, open-drain indicator pin for easy access. Diagnostic communication is independent of the switching control signals on the isolation barrier. Independent isolation channels and continuous fault monitoring ensure the highest equipment reliability and provide system operators with detailed information about the behavior of the loads on the other side of the switch and its isolation barrier.

Price and availability

The 4-channel Si834x isolation smart switch is in production and sampling now in a compact 9mm x 9mm DFN-32 package with exposed center pad (ePAD)