Points to note when selecting Schottky diodes

Points to note when selecting Schottky diodes

What are the parameters encountered by Schottky diodes in circuit applications, and how should they be selected?

1. The type of Schottky diode to be selected should be determined based on the output voltage Vo, current Io, heat dissipation, load conditions, installation requirements, and required temperature rise in the switching power supply. In general design, we need to leave a certain margin.

For example, VR only uses below 80% of its rated value, while IF uses below 40% of its rated value.

For example, if the working current is 8A and the voltage is 60V, it is recommended to use MBR20100CS

2. Pay attention to the heat dissipation and installation form of power Schottky diodes. To determine whether the product is naturally cooled or fan cooled, Schottky diodes should be installed in a location that is easily ventilated to improve product reliability. Thermal grease should be added between the TO-220 and TO-3P pipes and the radiator to ensure good contact between the pipes and the radiator.

3. The RC compensation network RC buffer for the correct selection of Schottky diodes. Due to the leakage inductance of high-frequency transformers and the junction capacitance of the diodes forming a resonant circuit at the cutoff, it can cause. Therefore, it is necessary to install an RC buffer in the power output to protect the safety of the transistor. In addition, RC networks can reduce output noise, decrease heat consumption of pipes, and improve product efficiency and reliability.