Some parameters that must be considered when choosing a Schottky diode

Some parameters that must be considered when choosing a Schottky diode

We often use Schottky diode in switching power supplies, but due to different manufacturers and other reasons, the performance varies greatly. When we choose Schottky diode, we must consider the following parameters:

Some parameters that must be considered when choosing a Schottky diode

We often use Schottky diode in switching power supplies, but due to different manufacturers and other reasons, the performance varies greatly. When we choose Schottky diode, we must consider the following parameters:

1. Conduction voltage drop VF

VF is the voltage drop across the diode when the Schottky diode is forward-conducting. When the current passing through the diode is larger, the VF is larger; when the diode temperature is higher, the VF is smaller.

Some parameters that must be considered when choosing a Schottky diode

2. Reverse saturation leakage current IR

IR refers to the current flowing through the Schottky diode when the reverse voltage is added to both ends of the Schottky diode. The reverse leakage current of the Schottky diode is relatively large. The choice of Schottky diode is to choose a Schottky with a smaller IR as much as possible. diode.

3. Rated current IF

Refers to the average current value converted from the allowable temperature rise of the Schottky diode during long-term operation.

 Schottky diode

4. Larger inrush current IFSM

Excessive forward current allowed to flow. It is not a normal current, but an instantaneous current, and this value is quite large.

Some parameters that must be considered when choosing a Schottky diode

5. Larger reverse peak voltage VRM

Even if there is no reverse current, as long as the reverse voltage is continuously increased, the Schottky diode will be damaged sooner or later. This kind of reverse voltage that can be added is not an instantaneous voltage, but a forward and reverse voltage that is repeatedly added. Since an AC voltage is applied to the rectifier, its maximum value is an important factor specified. The maximum reverse peak voltage VRM refers to the maximum reverse voltage that can be added to avoid breakdown. The current Schottky higher VRM value is 150V.

6. Larger DC reverse voltage VR

The above-mentioned larger reverse peak voltage is the peak voltage that is repeatedly applied, and VR is the value when DC voltage is continuously applied. For DC circuits, the maximum DC reverse voltage is important to determine the allowable and upper limit values.