Design considerations of the diode effective area with regard to the reverse recovery performance
Previous work has shown that the reverse recovery performance of fast power diodes at low currents becomes more critical because of snappy recovery. At low current densities, the shallower stored charge in the base region leads to a lower reverse recovery charge, and under high commutating di/dts it can lead to snappy recovery and total device failure. In this article, the effect of the current density on the reverse recovery performance is investigated by means of varying the diode effective area rather than the forward current. Simulation and experimental results have shown that at a given forward current and commutating di/dt, snappy recovery occurs for larger device areas with an increase in the reverse recovery charge. The outcome of this work will aid device and circuit designers in reducing the possibilities of device failures by choosing the correct size of diode or the optimum number of diodes in parallel for a certain application and rated current.
reverse recovery performance fast power diode circuit designer