Schottky Barrier Diodes
ROHM schottky barrier diodes provide low VF & IR and high ESD resistance.
Diodes are commonly used in a variety of circuits for rectification and protection. Moreover, as lower power consumption is required in most applications, the adoption of SBDs – which are more efficient than other diodes – is on the rise. However, if VF is lowered to improve efficiency, IR which is inversely related to VF will become higher. This increases the risk of thermal runaway, so it is important to balance both VF and IR when selecting SBDs for circuit design.
In response, ROHM strengthened its lineup of SBDs that balances small size with low VF and IR– characteristics demanded by the automotive sector. The market-proven RBR and RBQ series have been further expanded to include a lineup of compact high current, high voltage products that enable rectification and protection in a wider range of applications.
1. Low VF reduces loss
The RBR series achieves lower loss by reducing VF by 25% compared to ROHM conventional products of the same size while suppressing IR characteristics which is at tradeoff relation with low VF. This makes them ideal for automotive applications that require higher efficiency as well as laptops and other consumer electronics where greater energy savings are required.
In addition, chip size of RBR series is reduced while maintaining performance, resulting in a smaller package that minimizes footprint. For example, replacing the conventional 3.5mm×1.6mm size PMDU (SOD-123FL) package with the new 2.5mm×1.3mm PMDE decreases mounting area by approx. 42%.
2. New compact package added to ROHM’s comprehensive lineup
The RBR series now includes 12 new 2.5mm×1.3mm PMDE package products (6 for consumer + 6 for automotive). This brings the total lineup to 140 products (30V/40V/60V withstand voltages, 1A to 40A current) that expands applicability to include both automotive and consumer applications.
- Automotive Applications such as LED headlamps and car accessories
- Notebook PCs
1. Low IR ensures stable operation at high temperatures
The RBQ series utilizes proprietary barrier formation technology to achieve the optimum balance between VF and IR for switching power supplies. As a result, reverse power loss is decreased by 60% compared to ROHM’s conventional products, further reducing the risk of thermal runaway at high temperatures. This makes them ideal for automotive powertrain and industrial power supplies that operate in high temperature environments.
2. ROHM completes its lineup with new 100V products
The addition of 12 new 100V products (6 for consumer + 6 for automotive) to the RBQ series brings the total to 38 products comprised of both cathode common and single types in 45V/65V/100V withstand voltages and 10A to 30A of current.
- Industrial power supplies
- Engine ECUs
- Secondary rectification in AC/DC and DC/DC circuits
SBDs featuring superior efficiency are expected to replace conventional rectifier diodes and FRDs in automotive power supply exposed to high temperature. However, one drawback of SBDs is degraded IR characteristics at higher operating temperatures that can lead to thermal runaway, requiring products that provide stable operation at higher temperatures.
The RBxx8 series utilizes a barrier metal optimized for high temperature that significantly improves the IR characteristics (which is perhaps the most important challenge when using SBDs in automotive power supply). This ensures safe operation at high temperatures in automotive and industrial applications, eliminating the possibility of thermal runaway.
1. Replacing FRDs decreases application power consumption
Ultra-low IR allows ROHM to achieve high withstand voltage of 200V. This enables replacing 200V FRDs used in automotive systems with high efficiency SBDs. Therefore, the RBxx8BM/NS200 series reduces VF characteristics by 11% over conventional FRDs, contributing to lower application power losses.
2.Low heat generation reduces package size, contributing to greater space savings in a variety of applications
Reducing VF minimizes heat generation, enables users to adopt one smaller package size vs conventional solutions. ROHM is currently developing medium power packages, with plans to decrease mounting area by as much as 71% by replacing 5.9mm × 6.9mm FRDs with compact 2.5mm × 4.7mm products.
Automotive applications (i.e. xEVs) such as powertrain, industrial inverters, and various types of power supplies