ROHM’s New Schottky Barrier Diodes Achieve Class-Leading Reverse Recovery Time with 100V Breakdown Voltage by Adopting a Trench MOS Structure that Significantly Improves VF-IR Trade-Off

Ideal for automotive LED headlamps and other high-speed switching applications.

ROHM Semiconductor today announced new 100V breakdown Schottky Barrier Diodes (SBDs) that deliver industry-leading reverse recovery time (trr) for power supply and protection circuits in automotive, industrial, and consumer applications.

Although numerous types of diodes exist, highly efficient SBDs are increasingly being used in a variety of applications. SBDs with a trench MOS structure provide lower V_F than planar types and 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 of SBDs utilizing a proprietary trench MOS structure that simultaneously reduces both V_F and I_R (which are in a trade-off relationship) while also achieving class-leading trr.

Expanding on the four existing conventional SBD lineups optimized for a variety of requirements, 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% and overall switching loss by approximately 26% over general trench-type MOS products, contributing to lower application power consumption. The new structure also improves both V_F and I_R 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. As such, they are ideal for sets requiring high-speed switching, such as drive circuits for automotive LED headlamps and DC-DC converters in xEVs that are prone to generate heat.

Going forward, ROHM will strive to further improve the quality of its semiconductor devices, from low to high voltages, while strengthening its expansive lineup to further reduce power consumption and achieve greater miniaturization.

SBD Trench MOS Structure

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 V_F when applying voltage in the forward direction. At the same time, during reverse bias the electric field concentration is minimized, significantly decreasing I_R. As a result, the YQ series improves V_F and I_R by approximately 7% and 82%, respectively, compared to conventional products.

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%, contributing to lower application power consumption.

Application Examples

• Automotive LED headlamps
• xEV DC-DC converters
• Power supplies for industrial equipment
• Lighting