Analysis and Design of Boost DC-DC Converters for Intrinsic Safety

An improved boost DC-DC converter meeting the requirements of intrinsic safety is presented. The maximum values of output short-circuit discharged energy (OSDE) in CCM and DCM are analyzed, respectively. It is pointed out that the OSDE of a boost converter is the summation of the energy from the source and the inductor and the energy stored in the capacitor. It is proved that the maximal value of OSDE (MOSDE) in CCM is the largest within the total operating range. Once MOSDE is less than the minimum ignition discharged energy, the converter meets the requirement of output intrinsic safety. The design method of inductor and capacitor is proposed according to the requirement of output intrinsic safety and the desired output voltage ripple level within the total ranges of input voltage and the load. Experiment results are in positive with the analysis showing the feasibility of the described methods