Selection and Replacement Principles of Schottky Diodes — SUNMATE

Selection principles

A. For schottky diodes used in switching voltage stabilizing circuits, the schottky diodes with high operating frequency, short reverse recovery time and fast recovery shall be selected.

B Schottky diodes with small forward voltage drop shall be selected for low-voltage circuits.

C For the schottky diode of series power circuit, the schottky current large diode shall be selected, and the current and reverse working voltage shall be suitable for the schottky diode.

Replacement principle

A. Select the Schottky diode whose model parameters are basically the same as those of the original Schottky diode to replace.

B Schottky diode current large diode can replace Schottky diode current small diode, on the contrary, it cannot be replaced.

C The high reverse operating voltage Schottky diode can replace the low reverse operating voltage Schottky diode, on the contrary, it is impossible to replace it.

D The high operating frequency Schottky diode can replace the low operating frequency Schottky diode, but it cannot be replaced.

Precautions

Schottky diode will generate heat due to high forward current. Heating increases the leakage current (IR), and at the same time, the shell temperature and ambient temperature also increase. If the thermal design is incorrect, the heat generation will be higher than the heat dissipation, and the continuous heat generation will not reach the thermal balance. As a result, the leakage current (IR) also continued to increase, ultimately causing damage to the components. This phenomenon is called thermal runaway.