Application of Schottky Diodes in Power Supplies — SUNMATE

The most challenging part of Schottky diodes in power supply design is the always on 5 V output, as it means that designers need to use a separate AC/DC power supply, which takes up valuable space. Due to the need to maintain a compact size in the design, the only option for placing this additional circuit is close to the main output device, but when transmitting output current, the main output device will generate heat. This means that overheating is a significant risk and great caution must be exercised when designing.

Initially, Recom attempted to install planar Schottky rectifier diodes for DC/DC and AC/DC auxiliary power converters, but overheating remained a major challenge (especially under full load conditions).

To solve this problem, Recom chose to use the Trench Schottky diode provided by Youfeng Micro. Trench Schottky diodes are developed based on the original concept of Schottky diodes. The Trench concept aims to reduce leakage current and improve thermal stability. Compared to planar Schottky diodes, Trench Schottky diodes can improve switching performance.

The device is currently used in the RACM1200-V step-down converter, providing a 12 W fan output. Trench Schottky diodes are packaged in a small flat surface mount, capable of handling up to 2 A forward current and a maximum reverse voltage of 100 V. In addition, it also has a very low leakage current.