VI design for switching regulators characterization

The work here reported presents a virtual instrument (VI) for system frequency characterization in high noise presence. The automatic measurement system is based on a virtual instrumentation (VI) concept. It consists of a collection of programmable physical instruments, connected by GPIB bus (General Purpose Interface Bus) to a personal computer via a suitable interface. The software LABVIEW version 3.1 from National Instruments allows the use of the different functions of instruments via GPIB, it controls the measurement procedure and processes the incoming data from the physical instruments in order to obtain the desired performance indexes. The VI designed includes a synchronous sampling of both stimulus and response signals, a temporal of acquired signals, and DFT (Discrete Fourier Transform) processing algorithms in order to obtain frequency responses. As a result of this an important reduction of leakage and random noise errors is obtained. A PWM boost switching converter stimulated with multisinusoidal signals is used to validate the VI design