A radiated susceptibility test technique for PC boards implementing built-in-test or boundary scan designs

The authors describe a test technique and procedure for performing radiated susceptibility testing of printed circuit (PC) boards which implement built-in-test (BIT) or boundary scan designs. The measurement technique involves illumination of the circuit-under-test (CUT) with an electromagnetic plane wave generated in a TEM (transverse-electromagnetic) cell using a fiber-optic input/output (I/O) interface to the external test equipment. By isolating the CUT from the rest of the test environment, flaws in the EMI (electromagnetic interference) design/layout of PC boards can readily be identified and quickly retested using the recommended technique. Only a limited number of I/O pins must be interfaced to the digital test equipment when testing in BIT mode. A specific example of the use of these techniques and procedures as applied to a self-testing Am29034-bit microprocessor slice test circuit is also given