Silicon Labs' Si88xx family of products combine high-speed digital isolators with an isolated power supply. This integrated product for signal and power isolation provides a complete isolation solution to designers. The Si88xx has up to four high-speed digital isolation channels integrated with a modified fly-back topology based DC-DC converter. The DC-DC converter works in conjunction with an external transformer to provide up to 2 W of isolated power that can be used to supply the secondary side of the Si88xx as well as other circuits on the isolated side. The converter provides a high efficiency of 78%. It includes built-in secondary sensing and feedback through the isolation barrier back to the controller to achieve excellent line and load regulation for system stability. The converter also includes safety features like soft start, thermal detection, and cycle-by-cycle current limiting.

The Si88xx evaluation kit allows customers to evaluate the performance of the Si88xx digital isolators with an integrated dc-dc converter family of products. The evaluation board has the Si88241ED-IS populated to showcase the family. It is a complete solution for using a 3 V to 5 V primary supply to deliver up to 2 W on the secondary side at 3 V to 5 V supply voltage. Convenient test points are included to measure and observe time varying currents and voltages to calculate relevant parameters like efficiency, load/line regulation, and more.

Evaluation Kit includes:

• Si88241x based evaluation board
• Si88241ED-IS Quad digital isolator with integrated DC-DC converter
• UTB02581s 3 V to 5 V transformer
• Information card to get you started

Reference Design

Video: Si88xx Isolators with On-Chip DC-DC Converter