10 kV protection from digital isolators

November 05, 2015 // By Graham Prophet
Designed to protect industrial equipment against secondary lightning strikes, Silicon Labs has introduced a family of multi-channel digital isolators featuring a high-voltage isolation barrier designed to withstand 10 kV surges.

Using capacitive isolation technology, the Si86xxxT digital isolator family provides protection against secondary lightning strikes and increases system reliability in a wide range of industrial applications.

The digital isolator family delivers the fastest, most accurate timing specifications, highest noise immunity and reliability, lowest electromagnetic noise emissions and longest lifetimes under high-voltage conditions. Si86xxxT digital isolators are suitable for applications that must withstand a 10 kV hit such as microinverters, base station power supplies, process manufacturing equipment, motor controls and drives, industrial uninterruptible power supplies, metering equipment and battery management systems for electric vehicles.

In addition to requiring surge ratings of up to 10 kV, industrial equipment developers need isolation products with fast timing, high noise immunity, long lifetimes at high voltages, and a wide VDD and temperature range. Si86xxxT devices, Silabs says, satisfy all of these design requirements.

The Si86xxxT family includes a wide range of dual- to quad-channel devices in wide-body packages to accommodate diverse application needs with higher isolation ratings. Pin-compatible with existing digital isolators from Silicon Labs and other isolation suppliers, the Si86xxxT family offers substantial data rate, propagation delay, power, size, reliability and external bill of materials (BOM) advantages over legacy isolation technologies.

Operating parameters remain stable across wide temperature ranges and throughout the device service life for ease of design and highly uniform performance. The 10 kV surge capability qualifies Si86xxxT isolators as “Reinforced VDE” components, a standard of high importance for many industrial, telecom and automotive applications. Long lifetimes are particularly important to meet typical product lifetime for industrial uses.

All Si86xxxT digital isolators have Schmitt trigger inputs for high noise immunity, and these highly integrated devices only require VDD bypass capacitors, reducing BOM cost and complexity. The Si86xxxT devices support data rates up to 150 Mbps with propagation delays of 10 nsec. Enable inputs provide a single point of control for enabling and disabling the output drive.