May 13, 2013 – Silicon Labs (NASDAQ: SLAB, Country Manager In-gyu Kim), a global leader in high-performance analog-intensive mixed-signal ICs, today announced the industry's first drop-in replacement CMOS-based digital isolation solution (product name: Si826x family) to replace optocoupler isolated gate drivers (opto drivers). Supporting isolation ratings of up to 5 kV and surge protection of up to 10 kV, the new Si826x isolated gate driver series offers an ideal design configuration, package, and footprint to replace a wide range of opto drivers used in high-power motor control, industrial drives, solar power and EV/HEV inverters, switched-mode power supplies, and uninterruptible power supplies.

Faulty opto-drivers pose a vulnerability in motor control and other industrial power systems that require long-term reliability, extended warranty periods, and error-free operation for up to 20 years. Opto-drivers have inherent limitations due to vulnerable LED-based technology, which suffers from inconsistent output depending on input current, temperature, and lifespan. These variations can be eliminated with the Si826x isolated gate driver. The less variation there is, the simpler the system design becomes, as developers no longer need to worry about aging effects, particularly regarding input turn-on current. Furthermore, high reliability and extended device lifespan allow system manufacturers to support longer warranty periods while reducing product repair and replacement costs.

Based on Silicon Labs' proven digital isolation technology, the Si826x family is a product that provides a functional upgrade with pin and footprint compatibility with commonly used opto-driver products. The Si826x isolated gate driver mimics the operation of an opto-driver by modulating high-frequency carriers instead of LED light sources. The simplified digital architecture provides robust isolation to the data path without requiring any special considerations or preparations during the startup phase. While the input circuit mimics the characteristics of an LED, the Si826x products achieve high efficiency by requiring lower drive currents. The signal propagation delay of the Si826x products is independent of the input drive current, resulting in a consistently short propagation time (25 ns), less variation between units, and excellent flexibility in input circuit design.

The propagation delay and skew of the Si826x isolated gate driver are 10 times lower than those of opto drivers, improving response times for feedback loops and increasing system efficiency. The Si826x products offer excellent noise immunity, providing robust, glitch-free performance over long periods in harsh and noisy environments such as industrial motor control. Unlike opto drivers, isolated gate drivers provide stable performance over time and temperature variations without drift.

The Si826x gate driver is ideal for driving MOSFETs and IGBTs (insulated gate bipolar transistors) used in motor control and power inverter applications. Supporting gate drive voltages up to 30V and peak output currents ranging from 0.6A to 4.0A, the Si826x products provide best-in-class driving power suitable for MOSFET and IGBT applications, ensuring rapid turn-off and turn-on of external switching transistors for maximum efficiency.

"The Si826x isolated gate driver represents a significant advancement in isolation technology for industrial motor control by providing a drop-in replacement for older opto drivers with compatible package and footprint," said Mark Thompson, Vice President and Head of Access, Power, and Sensors product families at Silicon Labs. "The Si826x family offers developers a wide range of package and output options, significantly increasing design flexibility."

Price and supply

The Si826x isolated gate drivers are currently available for samples and mass supply and are offered in four package options: SOIC-8 (3.75 kV isolation rating), GW DIP-8 (3.75 kV isolation rating), SO-6 (5 kV isolation rating), and LGA-8 (5 kV isolation rating). These package types are compatible with common opto-driver packages in terms of pins and footprints, allowing for easy drop-in replacement with isolated gate drivers without the need to modify existing designs or PCB layouts. The Si826x family also supports various output currents. The Si8261Ax has an output current drive capability of 0.6 A, while the Si8261Bx can output up to 4 A. The Si8261xAx has a 5 V UVLO (output under-voltage lockout), the Si8261xBx has an 8 V UVLO, and the Si8261xCx offers a 12 V UVLO option.

The price of the Si826x family starts at $0.71 (USD) based on 10,000 units. To support developers in evaluating the performance of the Si826x family, Silicon Labs is offering the Si826xDIP8-KIT evaluation kit for $29. The evaluation board can be connected to the customer's existing board or connected to laboratory equipment for more detailed specification evaluation.