High efficiency 76V DC/DC buck converter

In recent years, with the increasing importance to conserve energy in all areas, there has been a push to achieve greater energy savings – even in the industrial equipment sector – through the use of high power semiconductor devices and power supply ICs. And with this comes a need to provide breakdown voltages higher than the input voltage to prevent damage due to instantaneous surge and transient voltages (such as those caused by lightning).

In response, ROHM leverages its power processes and vertically integrated production system to develop products for the industrial equipment market that demands long term, stable supply along with high reliability to enable continuous operation.

The BD9G341AEFJ utilises ROHM’s high voltage 0.6um BiCDMOS process to achieve a maximum breakdown voltage of 80V (the highest in ROHM’s non-isolated DC/DC converter line-up) and a continuous operating input range of 12 to 76V, while the analogue design technology results in the highest conversion efficiency in its class. In addition, multiple protection circuits minimise heat generation, even during output pin shorts (contact), preventing possible damage and increasing reliability versus conventional products. The compact 8-pin package requires fewer parts and reduces mounting area, contributing to easier PCB placement and end product miniaturisation.

Key features

1. 76V breakdown voltage
The 0.6um high voltage BiCDMOS processes are utilised to develop a non-isolated DC/DC buck converter with an integrated MOSFET featuring the industry’s highest maximum breakdown voltage in its class. As a result, support for input voltages up to 80V (maximum) and 76V (operation) is provided, ensuring sufficient margin against sudden surge voltages in communication infrastructure, factory automation equipment, industrial machinery and other applications that normally operate at 48V and higher, improving system reliability.

2. High efficiency
Power conversion efficiency in the 76V DC/DC converter class has been achieved by leveraging advanced analogue design technology. Efficiency is increased by 1.5% compared to conventional products during stable operation and by as much as 19% (300kHz oscillation frequency, 48V supply, 5V output), improving energy savings in industrial equipment.

3. Output pin protection prevents damage for improved reliability
Conventional protection functions normally cannot suppress heat generation during output shorts (contact), which can lead to overheating and even damage. In contrast, ROHM’s proprietary protection function minimises heat generation during accidental output shorts, preventing damage and improving system reliability.

4. Compact package reduces mounting area and requires fewer external parts
The BD9G341AEFJ is offered in a compact 8-pin package (4.9mm x 6.0mm, t=1.0mm) and features an integrated design that reduces the number of parts required from 17 to 12, simplifying end product design, BoM costs and development efforts.

Applications
Communication infrastructure such as switching and base stations, office telephone systems, routers and other equipment requiring 48V input. Motor devices exposed to high surge voltages (e.g. electric bicycles, vacuum cleaners, industrial controllers).