BD9G341AEFJ：DC-DC Converter Achieves Industry-Leading 80 V Rated Voltage, High EfficiencyPositioning and Target Market of 80 V Rated DC-DC Converter ICs

ROHM has announced the BD9G341AEFJ, a DC-DC converter IC incorporating a high-voltage (80 V) MOSFET. The high voltage rating of 80 V is in the top class of the industry for a non-isolated DC-DC converter IC with an internal power transistor, and positions this device as the highest-voltage model in ROHM’s lineup of DC-DC converter products. With increasing use in telecom-related areas, industrial equipment, and more recently in applications employing battery stacks, demand for high-voltage DC-DC converters continues to rise. However, only a limited number of manufacturers are supplying DC-DC converter ICs with rated voltages above 60 V, and a variety of such devices is not currently available.

What is the positioning of 80 V rated devices among DC-DC converter ICs, and what kind of markets are in need of such products?

In essence, the rated voltage is determined by the process technology used, not only for DC-DC converter ICs, but for semiconductor ICs and discrete components in general. Or rather, it should perhaps be said that a process technology providing the required rated voltage is used. From the standpoint of high voltage rating, there are for example numerous high-voltage MOSFET and diode products with voltage ratings of 500 V and higher. And, the internal MOSFETs of ROHM AC-DC converter ICs with internal MOSFETs are rated at 650 V.

Some readers may be wondering whether the 80 V rated voltage of the BD9G341AEFJ is particularly high. It is important to note that the BD9G341AEFJ has achieved its high voltage rating of 80 V as a non-isolated DC-DC converter IC. In the world of ICs for DC-DC converters, few DC-DC converter ICs have rated voltages exceeding 60 V, and only a small number of manufacturers offer such products.

The following table summarizes non-isolated DC-DC converter ICs in terms of their approximate rated voltage classifications and representative applications. As mentioned above, the higher the rated voltage, the fewer the number of manufacturers offering products, and the number and variety of products are also scarce. In other words, options for users are limited. In any case, under present circumstances a voltage rating of 80 V puts a product in the top class for devices of its kind.

Among markets that require 80 V-rated products, telecom applications are particularly prominent. The voltage commonly referred to as the “telecom 48 V” is an input voltage that, it is necessary to presume, includes considerable fluctuation, and as a rule, voltages from 36 V to 72 V (that is, 48 V -25%/+50%) should be assumed. Power supply ICs that support the telecom 48 V voltage include products rated at 72 V that are extended version of product lineups with 60 V rated voltage. This may be based on the assumption that the worst case of 72 V does not arise frequently, but clearly such devices provide almost no margin. In contrast, 80 V products can be said to be a safe choice for telecom applications.

• DC-DC converter