SDAA401 June   2026 ISOW1050 , ISOW3080 , ISOW6441 , ISOW6442 , ISOW6442-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Enhancing EMC Performance Through Board Design Techniques
    1. 2.1  HF Decoupling Capacitor on Pin 1 and Pin 16
    2. 2.2  Capacitor Bank and Relative Placement
    3. 2.3  Ferrite Bead π-Filter on Supply Rails
    4. 2.4  Isolated Copper Island (KOZ) Under Ferrite Beads
    5. 2.5  Common-Mode Choke on the CAN/RS-485 Cable (ISOW3080 and ISOW1050 Device)
    6. 2.6  Post Island Capacitor
    7. 2.7  Series Resistors or Low-Pass Filter on I/O Traces
    8. 2.8  Y-Capacitor Between GND1 and GND2 (Safety-Critical)
    9. 2.9  Interlayer Capacitor (Substrate Capacitor in the Isolation Region)
    10. 2.10 100µF Bulk Capacitor at VDD Input Rail
  6. 3Summary
  7. 4References

3 Summary

This application note suggested a comprehensive set of techniques to minimize radiated and conducted emissions, while maximizing immunity to external electromagnetic interference. These techniques include strategic placement of decoupling capacitors, ferrite bead π-filters, isolated copper islands, common-mode chokes, and Y-capacitors. These techniques emphasized the importance of PCB layout, referencing the ISOW6441DWEEVM, ISOW3080DWEEVM, and ISOW1050DWEEVM evaluation module designs as examples. These techniques can be applied to any design with isolators for achieving better EMC performance. Table 3-1 summarizes the EMC performance achieved with the ISOW64xx device using the techniques mentioned in this application note.

For more details on the EMC performance of this family of devices, refer to the EMC Compliance Report: CISPR/IEC Test Results for Isolators With Integrated Power application note.

Table 3-1 EMC Results for ISOW64xx
Test Type Standard Parameter Level | Class Result
Radiated Emission CISPR 32 Industrial Radiated Emissions Class B PASS
CISPR 25 Automotive Radiated Emissions Class 5 PASS
Radiated Immunity IEC 61000-4-3 Industrial Radiated Immunity 20V/m PASS
ISO11452-2 Automotive Radiated Immunity 100V/m PASS
Conducted Immunity IEC 61000-4-6 Conducted Immunity 15Vrms PASS
Conducted Emission CISPR 32 Conducted Emission Class B PASS
Magnetic Immunity IEC 61000-4-8 Magnetic Field 100A/m (Level 5) PASS
ESD AEC Q100-002 HBM ESD 2kV PASS
AEC Q100-011 CDM ESD 1.5kV PASS
IEC 62368-1 Surge Isolation 10.4kV PASS
CMTI VDE 0884-17 Common Mode Transient Immunity 100kV/µs (Minimum); 200kV/µs (Typical) PASS