Designers Have New Ways to Get Isolated

March 23, 2006 by Jeff Shepard

Analog Devices, Inc. (ADI), Optek Technology and Silicon Laboratories each announced components that provide design engineers new options for providing electrical isolation in a variety of applications. Silicon Labs Si844x uses chip-scale transformers fabricated in a standard CMOS process to deliver a high-speed, integrated four-channel isolator. Optek has targeted high-voltage applications with its new OPI1270 series of axial optical isolators while ADI extended its family of iCoupler® digital isolators with the industry's first products that provide both data and power isolation in a single package.

Silicon Labs' Si844x offers 50 percent faster data rates than existing digital isolators and consumes less than 12 mA per channel at 100 Mbps, making it suited for use in switch mode power supplies, Ethernet/CAN networks and isolated analog data acquisition. Based on a patented architecture, the Si844x uses a unique RF encoding/decoding scheme that provides a robust isolated data path and requires no special consideration or initialization. The Si844x products are as much as 1500x faster than other isolation technologies and exhibit stable operating characteristics over temperature, supply voltage and time.

"The Si844x is an extension of Silicon Laboratories' innovative digital power product portfolio and leverages patented technology to deliver highly integrated power solutions with unmatched performance," said Don Alfano, director of power products for Silicon Laboratories. "The digital isolator enables us to increase our offering to power supply customers by offering a single-chip, fully compliant solution that can be used in a variety of applications that require isolation, level shifting or ground-loop elimination."

ADI's proprietary isoPower™ technology integrates a micro-power supply with independent signal channels, eliminating the need for complex, sizeable, and costly combinations of optocouplers, transformers and other components, thereby reducing cost by as much as 70 percent and board space by as much as 80 percent.

"We are now leveraging our iCoupler technology to solve a challenging problem: isolating power along with data in a small space at a low cost. Our new iCoupler products with isoPower capabilities enable customers to achieve these savings as well as reduce development time," said Dick Meaney, vice president, precision signal processing group, Analog Devices.

Giving design engineers the ability to provide electrical isolation for high voltage circuits or signal transmission at a variety of distances, OPTEK's OPI1270 Series axial fiber optic isolator consists of a visible red LED emitter and a phototransistor detector housed in separate opaque molded plastic housings and coupled by a shrouded plastic fiber optic cable that gives the device extremely high noise immunity.

"The OPI1270 Series devices were designed for applications that require high voltage isolation between input and output or transmission of a signal from one location to another on the same or adjacent PC board," said Roland Chapa, OPTEK Technology's Assemblies Business Unit director. "The heavy-duty opaque housing and shrouded cable shields the optical signal from dust, dirt, oil and other particles, making the isolator ideal for contaminated environments."