The Schottky diode is a fast recovery diode that is a low power, ultra high speed semiconductor device. Its remarkable feature is that the reverse recovery time is extremely short (can be as small as a few nanoseconds), and the forward voltage drop is only about 0.4V. Schottky diodes are commonly used as high frequency, low voltage, high current rectifier diodes, freewheeling diodes, protection diodes, and also used as rectifier diodes and small signal detection diodes in circuits such as microwave communication. Commonly used in secondary power rectification of color TV, high frequency power rectification.

What is the difference between Schottky diodes and general rectifier diodes? What is special about Schottky diodes compared to general rectifier diodes? Let us study together today.

Schottky diodes utilize a metal-semiconductor junction as a Schottky barrier to produce rectification effects, as opposed to a P-N junction produced by a semiconductor-semiconductor junction in a typical diode. The characteristics of the Schottky barrier make the Schottky diode's turn-on voltage drop lower and increase the switching speed.

The turn-on voltage of the Schottky diode is very low. A typical diode will produce a voltage drop of about 0.7-1.7 volts when current is flowing, but the voltage drop of the Schottky diode is only 0.15-0.45 volts, which can increase the efficiency of the system.

The biggest difference between a Schottky diode and a general rectifier diode is the reverse recovery time, which is the time it takes for the diode to switch from the conduction state of the forward current to the non-conduction state. The reverse recovery time of a typical rectifier diode is about several hundred nS. If the high speed diode is lower than one hundred nS, the Schottky diode has no reverse recovery time, so the Schottky diode switching time of the small signal is about several tens of pS. The special large-capacity Schottky diode switching time is only tens of pS. Because the general rectifier diode will cause EMI noise due to reverse current during the reverse recovery time. Schottky diodes can be switched immediately, with no reverse recovery time and reverse current problems.