​Pay attention to these precautions when using Schottky diodes

Pay attention to these precautions when using Schottky diodes

Diodes will occasionally show some Glitch during operation. In fact, some small problems can be prevented and effectively prevented.

When using Schottky diodes, the following points should be noted:

The actual operating current of the circuit should be less than the forward additional current If of the Schottky diode, and generally not more than 60% of the additional current If.

2. The peak operating voltage of the applied circuit should be less than the highest reverse breakdown voltage Vrrm of the Schottky diode, and generally not more than 80% of the additional voltage Vrrm.

3. The actual operating temperature rise of the Schottky diode in the circuit should be less than the highest junction temperature Tjmax of the Schottky diode.

Regarding harsh environments, in order to ensure reliability, Schottky diodes should be derated for use, especially considering the selection of additional forward current.

5. For application circuits with high surge voltage or surge current, suppression and absorption circuits should be added.

6. The replacement of Schottky diodes should try to choose the original type, as different types of Schottky diodes have different forward voltage drop Vf, reverse breakdown voltage Vr, and reverse leakage current Ir. For example, replacing SR540 with SR5100, although the reverse breakdown voltage of SR5100 is higher than that of SR540, it seems that the replacement is not a problem. However, the forward voltage drop of SR5100 is higher than that of SR540. If used in the power circuit of a set-top box, it will cause excessive voltage violations of+5V and+12V, and other power consumption will increase compared to the original.