FPGA-Based Digital Network Analyzer for Digitally Controlled SMPS

This paper presents an FPGA-based digital network analyzer for digitally controlled switched-mode power supplies. Similar to standard network analyzers, the digital network analyzer can be used to validate converter models and the system design. The digital network analyzer can be built into the digital controller, resulting in an accurate measurement of the actual delays and non-idealities in the sampling and digital hardware. In addition, the approach requires relatively little additional hardware and/or software resources and reduces the costs in terms of equipment and engineering efforts. Experimental implementation on an FPGA and examples of 12 V-to-5 V 25 W buck converter open-loop and closed-loop frequency response measurements are shown