Date: 18/10/2011

Isolators from ADI achieve minimum creepage distance of 8mm

Analog Devices, Inc. has introduced the first packaging technology for digital isolators that achieve a minimum of 8-mm creepage distance required by global industry standards to ensure safe operation in high-voltage medical and industrial applications. Incorporating Analog Devices' iCoupler digital isolation technology, the CSA International- (Canadian Standards Association) certified package achieves 8.3-mm creepage and is designed for use in advanced medical diagnostic, measurement and monitoring, and industrial and instrumentation systems that operate up to 220-250 V AC.

ADI defines that creepage is the shortest distance over an insulating surface, such as an IC package, over which an arc may travel between two galvanically isolated conductors. ADI quotes an example for ensure adequate insulation, a 125-V working voltage requires 6 mm of creepage, while a 220-250-V working voltage requires a package with a minimum of 8 mm. The JEDEC standard 16 lead SOIC has 7.6 mm of creepage measured around the end of the package and does not meet the 220-250-V AC requirements to ensure safe operation in high-voltage medical and industrial applications. By increasing the length of the standard JEDEC package by 2.5 mm, ADI is able to enlarge the creepage path to 8.3 mm. The resulting package remains compatible with JEDEC standard footprint with minimal impact on board space.

"Analog Devices is the only semiconductor manufacturer to offer digital isolators in packaging that exceeds minimum insulation requirements for sensitive, high-voltage applications," said Patrick O'Doherty, vice president, Healthcare Group, Analog Devices. "The new SOIC packaging makes it possible for designers of 220-250-V medical equipment, such as patient monitoring devices, to migrate their design requirements from optocouplers to ADI's extensive digital isolator portfolio. Using a single iCoupler digital isolator can reduce overall board space while delivering four times the data rate and using 90 percent less power."
iCoupler Digital Isolators Available in 16-Lead Certified SOIC Package
Product Description Product Description
ADuM220x Dual-channel isolators
ADuM221x Dual-channel isolators
ADuM225x Isolators with non-latching bidirectional communication channels
ADuM240x Quad-channel isolators
ADuM4160 USB isolator
ADuM440x Quad-channel isolators
ADuM6000 Isolated dc-to-dc converter*
ADuM620x Dual-channel 5-kV isolators with integrated dc-to-dc converter*
ADuM640x Quad-channel isolators with integrated dc-to-dc converter*
ADM268xE 5-kV rms signal and power isolated RS-485 transceivers*


For more information visit: www.analog.com