Isolated industrial drive switches - 25 September 2019 - NuVision Electronics

Isolated industrial drive switches
25 September 2019, Power Electronics / Power Management

Silicon Labs has introduced a family of compact, robust isolated smart switches designed to drive any load, even in the harshest industrial environments. The new Si834x isolated switches are ideal for driving resistive and inductive loads such as solenoids, relays and lamps used in industrial control systems including programmable logic controllers (PLCs), I/O modules, relay drivers and servo motor controllers.

Each switch is galvanically isolated for safety using Silicon Labs’ CMOS-based isolation technology, offering better reliability and performance than legacy optocoupler-based isolation, including high common-mode transient immunity (CMTI) of more than 100 kV/µs.

The Si834x family supports high-side and low-side switch options, low on-resistance (145 m), up to 700 mA of continuous current compliant with the IEC 61131-2 standard, comprehensive protection and diagnostic reporting, and advanced configuration, monitoring and control for industrial automation systems. The switch 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) capable of controlling up to 128 channels with four MCU (microcontroller) pins.

Sophisticated switch and load monitoring techniques combined with fast responses to changing conditions make the Si834x switches highly robust, flexible solutions for driving a wide range of loads. Each switch can detect an open-circuit condition and is protected against over-current, over-voltage from demagnetisation (inductive kick or flyback voltage) and over-temperature conditions. A multi-voltage smart clamp efficiently handles an unlimited amount of demagnetisation energy.

The switches achieve enhanced load-driving performance and safer overload protection by employing rapid manipulation of switch impedance and clamp voltage. While other solutions entering into a fault state may shut down, the Si834x switches can continue operation in a constrained but functional state with reduced channel performance, improving system uptime.

The isolated switches feature a logic interface with eight separate diagnostic reports. Diagnostics are configured, monitored and cleared through SPI or exposed on active-low, open-drain indicator pins for easy access. Diagnostic communication is independent of the switch control signals across the isolation barrier.

For more information contact NuVision Electronics, +27 11 608 0144, gdeklerk@nuvisionelec.co.za, www.nuvisionelec.com