An Improved Boost DC-DC Converter Based on Intrinsic Safety and Its Design

As for a basic boost converter, the input power supply can´t be cut off thoroughly so as to meet the requirements of intrinsic safety by turning off its main switch in case of the abnormal conditions. An improved boost DC-DC converter is presented, it can realize intrinsic safety. The energy of the input power supply and inductor can be isolated from the output thoroughly by making the isolated switch turn off and the chief switch turn on in case of the output short-circuit. The ignition curves for capacitors and inductors are used as the criterion of the intrinsic safety. The design method of inductance and capacitance is obtained according to the requirement of intrinsic safety and the desired output voltage ripple level. An example is given with the results in positive to the analysis showing the feasibility of the improved circuit and design methods