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BD9G341AEFJ：DC-DC Converter Achieves Industry-Leading 80 V Rated Voltage, High Efficiency“High Voltage Rating of 80V “, “High Efficiency”, “High Reliability”, and “Compactness”

2017.08.24

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.

The BD9G341AEFJ was developed placing emphasis on the following four main areas:

1．Achieving an industry top-level high voltage rating of 80 V
The high voltage rating of 80 V was achieved by adopting a 0.6 μm high-voltage BiCDMOS process, which is ROHM’s own industry-leading power process. A large margin is secured with respect to sudden surges in 48 V input voltages for communication base stations, telecom equipment, FA equipment and the like, and so high reliability can be ensured in applications subject to strict power supply requirements but in which high availability is also sought.

2．Attaining the highest efficiency in the industry for an 80 V-class DC-DC converter device
In general, since high-voltage DC-DC converters are forced to have high requirements on the element characteristics and step-down ratio, their efficiency is inferior to that of low-voltage DC-DC converters.
Compared with similar existing ICs, however, the BD9G341AEFJ is capable of improving efficiency by a maximum of 19%, and by 1.5% in the steady state. (Both figures confirmed for an oscillation frequency of 300 kHz, input voltage 48 V, output voltage 5 V)

3．Boosting equipment reliability through protection functions to prevent failures and improve safety
ROHM’s own hiccup method was used for output short-circuit protection. In similar conventional devices, when an output short-circuit occurs a protection function is activated, but an overheated state results, often ending in device failure. The protection function incorporated into the BD9G341AEFJ performs periodic shutdown and restore, suppressing heat generation and automatically resetting once a fault has been eliminated. By means of this protection, failure of the power supply is prevented and the reliability of the application can be improved.

4．Reducing footprint and simplifying design through a compact package and reduced number of external components
A high-voltage (80 V) MOSFET is incorporated, and protection functions and external components have been integrated, so that the device can be provided in a simple, compact 8-pin HTSOP-J8 (4.9×6.0×1.0 mm) package. In comparisons with another similar device, the BD9G341AEFJ requires only 12 external components, versus 17 for the other product. Consequently the footprint can be reduced, and design and evaluation are simplified. In particular, designers will appreciate the considerable advantage in alleviating MOSFET selection and evaluation tasks as a result of integration of the MOSFET.

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