Can MDD quick recovery diodes and Schottky diodes be replaced? Now it is out of stock boom, many people are looking for replacement materials, but the fast recovery diode and Schottky diode are not replaceable!
Because Schottky diode reverse voltage is low, the forward voltage drop is small, suitable for low voltage rectification; Fast recovery high reverse voltage resistance, large forward voltage drop, suitable for high voltage rectification. Using Schottky instead of fast recovery is easy to breakdown (unless the pressure resistance is confirmed to meet the needs), and using fast recovery instead of Schottky loss is inefficient (unless efficiency is not considered). Compared with the Schottky diode, the fast recovery diode has a high forward voltage (about 0.3 volts higher) and a long reverse recovery time, which will reduce the current, increase the power consumption, and heat badly after being used instead, affecting the performance, stability and reliability of the whole machine. The high frequency characteristics of the fast recovery diode are much worse, and the forward voltage Schottky is much smaller than the fast recovery.
Replace the fast recovery diode and Schottky diode as much as possible with the original model, because different models of Schottky forward voltage drop Vf and reverse breakdown voltage Vr, reverse leakage current Ir are different. For example, replace SR540 with SR5100, although SR5100 has a higher reverse breakdown voltage than SR540, it seems that the replacement is no problem. However, the forward voltage drop of SR5100 is higher than that of SR540, and if it is applied in the STB power supply circuit, the +5V and +12V voltage will deviate from the normal value too much, and the power consumption will increase than the original.
However, the recovery time of the Schottky diode is in the nanosecond level, and the recovery time of the fast recovery diode is in the subtle level, so it can be replaced when the requirements are low.
