Schottky diode
pp 49-53
3.5 sotky diode (Schottky)
Besides diodes formed by contact of two semiconductors, there are passages of the contact metal and semiconductor type N. The metals behave like electronic semiconductor diode type R. This is called sotky diode (Schottky) from the homonymous researcher. The Schottky diode has characteristics similar to a simple PN diode, but has several advantages.
In contrast to the PN junction diode, when Poland was the proper time, the majority of players N-type semiconductor, which are the electrons enter the metal and bind to the free electrons of the metal. In this way there is no accumulation of charges occurs as a stripper in PN diode. Therefore the lifetime of electrons by reconnecting with the holes is minimal in contrast to the PN junction diode.
When a PN diode polarity change from reverse to correct, the reverse current, instant is equal to the forward current. But after a certain time, called the recovery time trr, the reverse current is very small. The Schottky diode is a diode with very little recovery time (about nsec) due to non-accumulation of cargo.
Diode Schottky, for the reasons stated above, is used in digital circuits require fast transition from the conduction (correct polarity) in the standard (reverse polarity) and interruptible power supplies (palmotrofodotika) for the same reasons. Also used in low voltage applications, because the contact metal - semiconductor presents lower potential barrier (0,3 V) from contact PN (0,7 V) (Low power Schottky TTL).
To Schottky diode symbol looks like the symbol of the PN diode, but is part of the descent to the letter S (Figure 3.5.1): The Schottky diode was discovered by
50s but only around 1970, with A · I> F, K
the development of integrated circuits;
Figure 3'5, 1 '
OA was too manufactured and use personal vol ° - Schottky diode symbol poieitai widely.
