1785-L40C15 Direct Current Rectifier Diode

The empirical algorithm of 1785-L40C15 is to require the maximum pulsation ΔImax of the output filter inductor current to be 20% of the maximum output current, which means that the output filter inductor current should be guaranteed to be continuous under the condition of 10% of the full output current. Then the above equation is desirable. Since the input voltage is variable, in order to ensure that the maximum pulsation of the filter inductor current does not exceed the maximum output current, Vin in the above equation is taken as Vin(max). The switching frequency of the full-bridge converter is fs, and the frequency of the square-wave voltage after the vice-side rectification is 2fs, i.e. = 2fs in the above equation.

The switching frequency of 1785-L40C15 is 100kHz, and the output rectifier diode should be selected as an ultra-fast recovery diode. For this circuit, the maximum reverse voltage on the rectifier is Vbr = Vin / K = 48 * 10 = 480 V. In the rectifier switching, there is a certain voltage oscillation, so we should consider the margin, you can choose 600 V rectifier diode. Rectifier diode in the ideal state, the maximum current flowing is equal to the maximum output current of 14A, considering the duty cycle caused by the current increase and a certain safety margin, you can choose 25A rectifier diode. This boost module uses IXYS DSEI30 ultra-fast recovery diode, rated voltage is 600V, rated current is 37A.