IL4822 / IL4622 / IL4685

13

NVE Corporation

11409 Valley View Road, Eden Prairie, MN 55344

(952) 829-9217

www.nve.com

YouTube.com/NveCorporation

iso-apps@ www.nve.com

Maintaining Creepage

Creepage distances are often critical in isolated circuits. In addition to meeting JEDEC standards, NVE isolator packages have

unique creepage specifications. Standard pad libraries often extend under the package, compromising creepage and clearance.

Similarly, ground planes, if used, should be spaced to avoid compromising clearance. Package drawings and recommended pad

layouts are included in this datasheet.

Inherently Low EMI

Electromagnetic compatibility is regulated by international standards such as IEC 61000-4-x and CISPR 32. Although system-

level performance depends on board design and layout, these components incorporate features to reduce radiated EMI.

The DC-to-DC convertor oscillator operates above 88 MHz, where emission limits are higher since there is less risk of interference

with common commercial radio and television broadcasting.

Frequency-hopping technology dramatically reduces peak EMI, and synchronous rectification and PWM control are avoided,

resulting in inherently low EMI. This inherently low EMI eliminates the need for shielding or external mitigation components such

as ferrite beads. The parts are fully EN 55032 CISPR 32 Class B compliant with no EMI mitigation components and only 12 pF of

input-to-output stitching capacitance. The capacitance can be created in a four-layer PCB by extending the GND1 and GND2

ground planes into the PCB isolation area. External stitching capacitor components are generally not recommended due to parasitic

inductance above one gigahertz. See Fig. 23 for a typical schematic, and Application Bulletin AB-29 for a recommended PCB

layout.

High Magnetic Immunity

These parts are fully compliant with IEC 61000-6-1 and IEC 61000-6-2 magnetic immunity standards.

The IsoLoop Isolator’s Wheatstone bridge configuration and differential magnetic field signaling ensure excellent EM

immunity. Immunity to external magnetic fields is even higher if the field direction is “end-to-end” (rather than to “pin-

to-pin”) as shown at right.