In recent years, more efficient use of electricity has become necessary to meet the growing global energy demand. This is especially true for white goods and industrial equipment that consumes large amounts of energy, such as electric vehicle charging stations. This equipment requires not only high electrical efficiency but also reduced workload to mitigate noise in the circuit design. In response to this situation, ROHM has developed diodes that combine a low forward voltage (VF) for more efficient operation with fast turn-on characteristics that provide lower losses and ultra-low noise during shutdown.
Optimized device structure and materials allow the RFL/RFS series to achieve the optimal balance of voltage (VF) and trr, important characteristics for power supply diodes (FRDs) that are typically in a trade-off relationship. The low-VF RFL series reduces VF by approximately 3.2% and trr by 8.3% compared to the conventional RFN series, while the RFS series reduces VF by approximately 17.9% compared to the conventional RFUH series. Both products contribute to higher power supply efficiency thanks to an optimized design based on circuit requirements. Furthermore, very low-noise diode recovery characteristics are achieved, helping to reduce both component workload and noise.
In the future, ROHM will continue to expand the RFL/RFS series package range to support the automotive industry, while also broadening applicability by reducing power consumption.
RFL Series (Low VF) 
Product Range
RFS Series (high-speed trr)
Applications
PFC (power factor correction) circuits in air conditioners, washing machines, refrigerators, etc.
Secondary rectifier circuits in electric vehicle charging stations and similar equipment.
Inverter circuits in machine tool robots, compressors, etc.
Power supplies for servers, base stations, etc.
Examples (of circuit topology)
Topology Selection:
When designing power supply circuits, it is necessary to select a circuit configuration (topology) that meets the required specifications for input/output voltages, power, isolation, and other factors. ROHM offers a selection page that recommends optimal products for various topologies.
https://www.rohm.com/topology
