Built-in self-test for automatic analog frequency response measurement

We present a built-in self-test (BIST) approach, based on a direct digital synthesizer (DDS), for functional test of analog circuitry in mixed-signal systems. DDS with delta-sigma noise shaping is used to generate test signals with different frequencies and phases. The DDS-based BIST hardware implementation can sweep the frequencies through the interested bands and thus measure the frequency response of the analog circuit. The proposed BIST approach has been implemented in Verilog and synthesized into a field programmable gate array (FPGA). The actual device under test (DUT) was implemented using a field programmable analog array (FPAA) to form a complete BIST testbed for analog functional tests.