A digitally controlled programmable power supply used in a vaporizer

A digitally controlled programmable switch mode synchronous step down DC-DC power supply for a vaporizer used in a spectrometric instrumentation analyzer is designed taking into consideration the delays caused by the analog to digital converter, digital to analog converter and the discretization process of the control coefficients. The control method used is average current mode control. Because the control method is implemented using a microcontroller the power supply can be transformed from a voltage source to a current source through the PC interface without the need to compute new values for the two proportional integral (PI) controllers. The simulations and experimental results are presented, compared and conclusions are drawn about how the discretization process and the delays affect the phase margin and the design process of the power supply.