What is the forward current of a Schottky diode

Typically, the rated current is defined as the average rated current that the Schottky diode can pass. However, some of them are preceded by a square wave, that is, a square wave current that can be passed with an average value of 10 A. Some tests are based on direct current, which means that it can pass 10 amps.

Theoretically, for silicon diodes, the diode with the square wave as the test condition can pass a larger DC current, because the square wave with the same average current will cause greater losses to the diode than the DC current.

So is a 10A Schottky diode guaranteed to be able to pass through a 10A current?

Not necessarily, this is related to temperature, when your heat dissipation conditions are not good enough, then the current that can pass through the Schottky diode will be limited by the junction temperature.

It is the working current when the diode is forward conducted, and the reverse current is the leakage current when the diode is in reverse bias.

The differences between Schottky diodes and ordinary diodes are as follows:

1. The forward pressure drop value is different

Directly use a digital multimeter to measure (small current) ordinary diodes are above, Schottky diodes are below, ordinary diodes are left and right when high current, and Schottky diodes are below; SR350 stands for 3A50V. In addition, the withstand voltage of Schottky diodes is generally below 100V, and there is no voltage above 150V.

Second, the characteristics are different:

The most important feature of Schottky diodes is that the forward voltage drop vf is relatively small. At the same current, its forward voltage drop is much smaller. In addition, it has a short recovery time. It also has some disadvantages: the withstand voltage is relatively low, and the leakage current is slightly larger.

Third, the pressure resistance is different:

The withstand voltage of ordinary silicon diodes can be made higher, but its recovery speed is low, and it can only be used for low-frequency rectification.

The withstand voltage energy of Schottky diodes is often low, but its recovery speed is fast and can be used in high-frequency occasions, so the switching power supply uses this diode as the rectifier output, despite this, the temperature of the rectifier tube on the switching power supply is still very high.

Diode Characteristics:

The diode has unidirectional conductivity, and a forward voltage is added to the diode, and when the voltage value is small, the current is very small; When the voltage is exceeded, the current begins to increase exponentially, which is usually called the turning on voltage of the diode; When the voltage reaches about that, the diode is in a fully on-state, which is usually called the on-voltage of the diode, which is represented by the symbol ud.

For germanium diodes, the turn-on voltage is and the on-voltage ud is about. When the voltage value is small, the current is very small, and its current value is the reverse saturation current is.

The maximum operating frequency is the upper limit frequency at which the diode operates. Since a diode is the same as a PN junction, its junction capacitance is composed of barrier capacitance. Therefore, the value of the maximum operating frequency depends mainly on the size of the p-n junction capacitance. If this value is exceeded. The unidirectional conductivity will be affected.

1.The forward voltage drop of Schottky diodes is much lower than that of fast recovery diodes, so their own power consumption is small and the efficiency is high.

2.Due to the extremely short reverse charge recovery time, it is suitable for operation at high frequencies.

3.Able to withstand high inrush currents.

4.In the past, the reverse withstand voltage of Schottky tube was generally below 200V, but now the latest technology can achieve products up to 1000V, and the market application prospect is very broad.

5.At present, there are several common Schottky tube junction temperature points on the market (the higher the junction temperature, the better the high temperature resistance of the product.) i.e. operating below this temperature will not cause failure).

Summary. The unidirectional conductivity of Schottky diodes is caused by the band structure of the diode's semiconductor material and the formation of the p-n structure.

The unidirectional conductivity of Schottky diodes is caused by the band structure of the diode's semiconductor material and the formation of the p-n structure.

I'm still a little confused, can you be more detailed?

The Schottky diode is a single-conductive component due to the asymmetry of its internal structure and the difference in materials. The positive end of the Schottky diode is composed of a high-doped p-type semiconductor and a low-doped n-type semiconductor, while the negative end is a metal contact area, which cannot be broken down by reverse voltage with the semiconductor, which makes the Schottky diode have low resistance when it is forward biased, and high resistance when it is biased in the reverse direction, and then exhibit unidirectional conductivity. In addition, Schottky diodes can change the magnitude of their resistance by adjusting the characteristics of the interface of metal semiconductors, which makes them widely used in integrated circuits.