What is Schottky diode thermal runaway?
As the body temperature of the Schottky diode increases, the leakage current If increases and the forward voltage Vf decreases, which will cause a common problem called thermal runaway. The increased temperature will cause the temperature to increase further until the component is damaged. As with any Schottky diode, there is a trade-off in the design. That is, this device is either optimized for forward voltage drop or optimized for low leakage current. Therefore, if low pressure drop is selected, the leakage current will be higher, and vice versa. In actual application, not only the value of forward voltage drop or leakage current must be observed, but also the result of their actual operation. Both the forward voltage drop and the leakage current will change with temperature. When the temperature rises, the forward voltage drop will decrease, reducing the heat dissipation as the Schottky diode heats up. Unfortunately, the leakage current increases as the temperature of the Schottky diode increases. Therefore, the higher the temperature, the more leakage current, and the more internal power dissipation, which makes the Schottky diode temperature higher, thereby increasing the leakage current again, and so on.