Multichip packages and systems-on-a-chip (SoCs) are widely used to satisfy the demand for high-performing electronic devices. And with emerging applications requiring higher operating frequencies, the circuits used for these applications are becoming more complex. One factor to account for is the large amount of parasitic emissions that can be generated by such complex integrated circuits (ICs). In the application note, “Integrated Circuits (ICs) and Component EMC Testing,” AR RF/Microwave Instrumentation discusses techniques that can be utilized to test ICs for electromagnetic compatibility (EMC) and electromagnetic interference (EMI).
The application note explains the fundamentals for both EMI and EMC testing. Essentially, EMI (emissions) testing determines the RF interference that’s radiated or conducted from a component. Emissions from a component can cause nearby components/equipment to malfunction. EMC (susceptibility) testing determines the immunity of a component/device to external RF interference conducted or radiated into that component/device.
Following that discussion is an explanation of the TEM cell test method. It’s used to measure the emissions or immunity of an IC from 150 kHz to 1 GHz. The document notes that either a two-port TEM cell or a one-port TEM cell can be used.
The note breaks down two standard test methods: the bulk current injection (BCI) method and direct power injection (DPI) method. The BCI method determines the immunity of an IC in the presence of conducted RF disturbances. And the DPI method determines the immunity of an IC as a function of the effective power transmitted to the circuit. Illustrations of both test setups are presented.
Another point highlighted in the app note is that cable harnesses and/or printed-circuit-board (PCB) traces can form efficient antennas. Thus, an IC receives unwanted RF energy through the pins that are connected to the wires of cables. That means the EM immunity of an IC can be characterized by conducted RF disturbance (i.e., RF forward power) rather than field parameters. Lastly, the document mentions specific AR amplifiers that can be used for BCI and DPI component testing, as well as the company’s emcware test software.
AR RF/Microwave Instrumentation, 160 Schoolhouse Rd., Souderton, PA 18964; (215) 723-8181