What should be paid attention to when selecting fast recovery diodes?
⑴ Correct selection of packaging form
When selecting the packaging form, the advantages and disadvantages of various packaging forms shall be comprehensively considered according to the requirements of the application site for environmental adaptability, so as to determine the packaging form of the device, so as to meet the use requirements and give consideration to the economy.
(2) The maximum rating of the device shall not be exceeded
The limit value of the operating conditions and environmental conditions under which the device can be used safely is called the maximum rating of the device. No matter how bad the working conditions and environmental conditions are, the device is not allowed to exceed or exceed the specified limit value instantaneously during use. Only when it is used below this limit value, can the device work reliably and give full play to its functions. Otherwise, the device may suffer from parameter degradation, performance degradation, greatly shortened life, and even damage and failure. Therefore, when selecting components, the circuit designer shall fully consider the changes of electrical conditions (such as current and voltage changes, load changes, signal changes, circuit control adjustments, components and equipment changes, etc.) and environmental conditions during the whole working life of the components, so that they do not exceed the maximum allowable rating of the components. In addition, because the parameters of the maximum rating of devices are interrelated, consideration must be given to both design and use.
(3) Derating
Temperature is an important factor affecting device life. The higher the junction temperature, the greater the probability of failure. Therefore, the junction temperature of the device should be controlled within the allowable range to prevent the device from overheating and causing failure.
Derating is an effective measure to prevent overheating of devices. In order to improve the reliability of the device, the specified parameters of the device should be derated. The parameters (derating factor) that need to be derated when the device is used include: voltage, current, power, working junction and ambient temperature. 2、 Typical derating use of triode
