SPS IPC Drives 2015: ROHM Shows The Industry’s First AC/DC Converter Control IC for SiC Drive

Enables to use of SiC MOSFET to achieve greater energy savings and miniaturization in industrial applications 

Willich-Münchheide/Nuremberg, November 24^th, 2015 – ROHM shows its recently announced AC/DC converter control IC designed specifically for SiC MOSFET drive in industrial equipment such as servers and other large power applications at SPS IPC Drives (Hall 1, Booth 320).

The BD7682FJ-LB allows the easy implementation of SiC-MOSFETs to an AC/DC converter AC/DC converter design has proved challenging when using discrete configurations due to the large number of components required. In contrast, ROHM’s latest product provide a high integrated solution and creates new standards for energy savings and miniaturization while supporting the adoption of SiC power semiconductors that provide breakthrough levels of efficiency and performance.

Compared to silicon MOSFETs used in conventional AC/DC converters, SiC MOSFETs enable AC/DC converters with improved power efficiency by up to 6%. Furthermore, components used for heat dissipation are not required (50W Class power supplies), leading to greater compactness. The specification of BD7682FJ-LB also include multiple protection functions that enable support for high voltages up to 690VAC, making them ideal for general industrial equipment while improving reliability.

In recent years there has been an increasing trend to conserve energy in all areas. This includes high voltage industrial equipment applications. To achieve this targets it’s necessary to adopt advanced power semiconductors and power supply ICs. Among these, SiC power semiconductors are expected to gain ground over silicon solutions due to their higher voltage capability, greater energy savings, and more compact form factor.

However, until now there has not been a control IC that can sufficiently draw out the performance of SiC MOSFETs, particularly in AC/DC converter systems. As a result designers are faced with numerous problems related to power consumption and stability in a variety of high power applications.

To meet these needs, ROHM utilizes market-proven analogy technology with SiC power semiconductor expertise to develop the industry’s first AC/DC converter controller specialized for driving SiC MOSFETs. And going forward ROHM will continue to pioneer industry-leading solutions, including the development of new AC/DC converter control ICs with integrated SiC MOSFETs.

Availability: The product is available (samples).

Key Features

1． Maximizes SiC MOSFET performance for breakthrough energy savings

The BD7682FJ-LB integrates a gate drive circuit optimized for SiC MOSFET drive by combining analog design technology with SiC power semiconductor development expertise. In addition, a quasi-resonant system delivers lower noise and higher efficiency vs conventional PWM methods, making it possible to maximize the performance of SiC MOSFETs used in AC/DC converters, resulting in significant power savings.

2. SiC MOSFET contributes to unmatched miniaturization

Unlike with conventional Si MOSFETs, adopting SiC MOSFETs in AC/DC converters eliminates the need for components used for heat dissipation, contributing to smaller, lighter AC/DC converter designs. Support for higher switching frequencies (i.e. 120kHz) is also ensured, expanding applicability while improving efficiency.

3．Multiple protection circuits support high voltage operation up to 690VAC

Various protection circuits enable high voltage operation in AC/DC converters up to 690VAC – ideal for general 400VAC industrial applications. And in addition to overvoltage protection for the supply voltage pin and brown in/out (undervoltage) countermeasure for the input voltage pin, overcurrent and secondary overvoltage protection functions are included, enabling continuous operation in industrial equipment while improving reliability considerably.

SiC MOSFET Advantages

SiC MOSFETs provide several advantages over Si MOSFETs in the high voltage region, including lower switching and conduction losses, high power compatibility, and increased resistance to temperature changes. Leveraging these benefits makes it possible to improve power conversion efficiency, miniaturize components for heat dissipation, increase operating frequency to support smaller coils and more, resulting in increased power savings, lower component count, and smaller mounting area.

Terminology

・SiC (Silicon Carbide)

A compound semiconductor composed of silicon and carbide. Provides characteristics and performance superior to silicon, making it the most viable successor to silicon in the power semiconductor field.

・AC/DC Converter

A type of power supply that converts AC voltage to DC. Generally, devices that operate on DC voltage require additional components to connect to an AC outlet/power source.

・MOSFET (Metal Oxide Semiconductor Field Effect Transistor)

A type of basic semiconductor transistor. External voltage is supplied to turn the transistor ON/OFF. It can also be used as a switching device to control current flow.

・Power Semiconductor

A type of semiconductor that converts voltage and/or current depending on the application, with performance directly linked to the power efficiency of the device and system. Compatibility with large voltages and currents is needed.