Rohm 100V SBDs achieve 15ns reverse recover time
Proprietary trench MOS structure improves VF-IR trade-off
Rohm has developed 100V breakdown Schottky barrier diodes (SBDs) that are said to deliver industry-leading reverse recovery time (trr) for power supply and protection circuits in automotive, industrial, and consumer applications.
SBDs with a trench MOS structure that provide lower VF than planar types enable higher efficiency in rectification applications. One drawback of trench MOS structures, however, is that they typically feature worse trr than planar topologies – resulting in higher power loss when used for switching.
In response, Rohm developed a new series utilising a proprietary trench MOS structure that simultaneously reduces both VF and IR (which are in a trade-off relationship) while also achieving class-leading trr.
The YQ series is Rohm’s first to adopt a trench MOS structure. The proprietary design achieves class-leading trr of 15ns that reduces trr loss by approximately 37 percent and overall switching loss by around 26 percent over general trench-type MOS products, contributing to lower power consumption. The new structure also improves both VF and IR loss compared to conventional planar type SBDs. This results in lower power loss when used in forward bias applications such as rectification, while also providing less risk of thermal runaway which is a major concern with SBDs.
The trench MOS structure is created by forming a trench using polysilicon in the epitaxial wafer layer to mitigate electric field concentration. This reduces the resistance of the epitaxial wafer layer, achieving lower VF when applying voltage in the forward direction. At the same time, during reverse bias the electric field concentration is minimised, significantly decreasing IR. As a result, the YQ series improves VF and IR by approx. 7 percent and 82 percent, respectively, compared to conventional products.
And unlike with typical trench MOS structures where trr is worse than planar types due to larger parasitic capacitance (resistance component in the device), the YQ series achieves an industry-leading trr of 15ns by adopting a unique structural design. This allows switching losses to be reduced by approximately 26 percent, contributing to lower application power consumption.
