April 3, 2015 – Silicon Labs (Country Manager: Baek Woon-dal), a specialist in digital isolators and power products for industrial automation, has launched a family of high-speed, multi-channel digital isolators designed to provide integrated, highly integrated solutions for signal and power isolation. Silicon Labs’ new Si88xx isolators feature an integrated DC-DC converter delivering 78% efficiency, supplying up to 2W of power, and offering high immunity to very low electromagnetic interference (EMI) and noise. The Si88xx family enables reduced system costs and accelerated time-to-market, while improving application reliability in harsh and noisy operating environments, including factory automation, process control, programmable logic controllers (PLCs), solar inverters, and automotive battery management.

Silicon Labs' Si88xx isolator family meets the need for plug-and-play isolated power supplies in industrial automation. Developers often have to design isolated power supplies from scratch, which can be a time-consuming, wasteful, and costly process requiring numerous discrete components. Discrete power isolation solutions typically utilize field-effect transistors (FETs), controllers, single-channel isolators or optocouplers, and other components. In contrast, designs based on multi-channel Si88xx isolators require only a single small ferrite core transformer and a small number of discrete passive components. Solutions based on Si88xx isolators ultimately eliminate the need for multiple design iterations and improve noise immunity and power efficiency while reducing bill-of-materials (BOM) costs and design complexity.

The Si88xx digital isolator receives power from the primary side and supplies up to 2W of isolation power to the secondary side. The isolator provides up to four high-speed digital isolation channels with excellent timing characteristics, featuring virtually no propagation delay and no jitter, thereby enabling longer system lifespans at high voltages. These signal isolation characteristics are critical to system designers for industrial automation, battery management, and motor control applications that require long-term performance maintenance. Compared to conventional isolation technologies, including optocouplers, the low-power, high-speed Si88xx digital isolation channels offer significant advantages in terms of practical data rates, propagation delay, and reliability. The Si88xx family supports data rates up to 100 Mbps, and the Si8xx achieves a propagation delay of just 23 ns.

The Si88xx isolator integrates Silicon Labs' proven and patented digital isolator technology with an on-chip isolated DC-DC converter that provides a refined output voltage of 3.3 V or 5.0 V (or over 5 V when using external components) at peak output power levels of up to 2 W. The robust DC-DC converter architecture is constructed with a ferrite-core isolated transformer and provides sufficient power to supply the secondary isolator as well as other components such as RS-485 or CAN transceivers, microcontrollers, and analog-to-digital converters (ADCs). The DC-DC converter is based on a modified flyback architecture with feedback to the controller, including secondary sensing and external correction. Power switches not only use zero voltage switching (ZVS) techniques to minimize power loss but also utilize dithering techniques to reduce EMI.

The Si88xx isolator features a built-in soft-start function that provides inrush current protection and integrates various safety features, including cycle-by-cycle current limiting and heat detection/shutdown capabilities. The integrated DC-DC converter incorporates secondary sensing and feedback signaling functions, eliminating the need for additional opto-feedback paths while enabling appropriate line and load regulation for superior system stability. The DC-DC converter also offers shutdown options and user-adjustable switching frequencies to fine-tune the EMI profile to meet the developer's individual application requirements.

Ross Sabolcik, Vice President and General Manager of Silicon Labs’ Analog, Power, and Sensor Products, said, “The new Si88xx family delivers the superior EMI performance, high data rates, and reliability of Silicon Labs’ digital isolator technology to demanding applications requiring both signal and power isolation along with higher channel number density. The Si88xx digital isolators provide industrial system developers with an integrated plug-and-play solution that dramatically simplifies their power supply applications while ensuring long-term performance and reliability.”

Product Price and Supply Information

Samples and production quantities of the Si88xx digital isolator are currently available in a 20-pin WB SOIC package. Order options include selection of DC-DC converter functions, isolated channel configuration, and fault protection modes. All Si88xx products are certified by UL, CSA, VDE, and CQC. The Si88xx product family is priced at $2.42 USD for 10,000-unit quantities. To assist developers in evaluating the performance of the Si88xx isolators, Silicon Labs' Si88xx ISO-KIT evaluation kit is currently available for $29 USD MSRP. Detailed information on Silicon Labs' Si88xx digital isolators, as well as information on purchasing samples and development tools, can be found at www.silabs.com/Si88xx.