A CAD simulator based on loop gain measurement for switching converters

A CAD simulator for power converters on the MATLAB platform is presented. It employs an interpolation technique in determining switching instants in the time domain accurately. A small sinusoidal source is then injected to obtain the steady state time response and is followed by FFT to obtain the resultant amplitude and phase. By varying the injected frequency, loop gain frequency response is obtained. Issues on loop gain measurement are discussed. A cost-effective set-up is then presented. The methods of simulation and measurement can be applied in power converters of any topology.