SiC power semiconductors offer greater energy efficiency, miniaturization, and higher voltage capability than existing Si power devices. In recent years, the growing concern for energy conservation has driven the adoption of SiC power semiconductors in 400V AC industrial applications. Furthermore, industrial equipment often features a main power supply circuit and an integrated auxiliary power supply that powers various control systems. In these applications, energy conservation presents a significant challenge, as inefficient high-voltage Si MOSFETs and IGBTs with high switching losses have been widely adopted.
In response, ROHM has led the industry in developing a variety of ICs that maximize the performance of SiC power semiconductors, becoming the first company to offer AC/DC converter control ICs to drive high-voltage, low-loss SiC MOSFETs in 2015. Now, we have created the industry's first AC/DC converter ICs with integrated SiC MOSFETs, simplifying the adoption of SiC MOSFETs in AC/DC converters for industrial equipment.
The BM2SCQ12xT-LBZ series comprises the industry's first AC/DC converter ICs with integrated 1700V SiC MOSFETs. This series achieves remarkable power savings and facilitates efficient AC/DC converter configuration by resolving many of the design challenges that affect discrete-component-based solutions. Integrating a SiC MOSFET and optimized control circuitry for auxiliary power supplies in industrial equipment into a single package significantly reduces the number of components compared to conventional configurations (from 12 components plus a heatsink to a single IC). It also reduces both the risk of component failure and the development effort associated with SiC MOSFETs. Furthermore, this product improves energy efficiency by 5% (and reduces power loss by 28%). These features translate into a dramatic size reduction, improved reliability, and superior energy savings in industrial applications.
In the future, ROHM will continue to develop power semiconductors such as SiC devices along with integrated circuits to control them, providing optimized solutions that contribute to greater energy savings and performance in industrial equipment.
Key Features
The BM2SCQ12xT-LBZ series utilizes a dedicated package to incorporate a 1700V SiC MOSFET along with a control circuit (i.e., a SiC MOSFET gate drive circuit) optimized for auxiliary power supplies in the industrial sector.
These advanced AC/DC converter ICs offer the following features that contribute to the proliferation of SiC MOSFET-equipped AC/DC converters by improving the reliability, energy efficiency, and compactness of 400V AC industrial equipment:
1. Achieves significant miniaturization by replacing 12 components plus a heatsink with a single package.
ROHM's latest product series replaces up to 12 components (AC/DC converter IC, 800V Si MOSFET x 2, Zener diode x 3, resistor x 6) plus a double heatsink with a single package, drastically reducing the number of external parts required. Furthermore, the high voltage capacity and voltage noise of the internal SiC MOSFET allow for a reduction in the size of the components used for noise suppression.
2. It reduces man-hours and risk, while the multiple built-in protection functions provide superior reliability.
The monolithic design reduces the labor hours required for component selection and reliability assessment of blocking and drive circuits, while minimizing the risk of component failure and simplifying the development burden for SiC MOSFET adoption. It also integrates functions such as overload protection (FB OLP), overvoltage protection (VCC OVP) of the supply voltage pin, and high-precision thermal shutdown (TSD, implemented via the built-in SiC MOSFET), along with overcurrent protection and secondary overvoltage protection. The incorporation of multiple protection circuits for industrial power supplies requiring continuous operation significantly improves system reliability.
3. It maximizes the performance of the SiC MOSFET to dramatically improve energy savings.
The integrated gate driver circuit optimized for the internal SiC MOSFET improves efficiency by up to 5% compared to conventional Si MOSFETs (ROHM study, April 2018). Furthermore, a pseudo-resonance method is adopted for the control circuit, enabling more efficient operation with lower noise than conventional PWM modulation systems, thus minimizing the effects of noise on industrial equipment.
Advantages of SiC MOSFETs:
SiC MOSFETs offer several advantages over their silicon counterparts at high voltage levels, such as lower switching and conduction losses, higher power handling capacity, and greater stability against temperature changes. This allows for a reduction in the number of components required and the mounting surface area, while also improving energy savings when used in AC/DC and DC/DC converters. For example, by reducing the size of heat dissipation components and the inductor through operation at a higher switching frequency.
Product range
Application examples
- General purpose inverters
- AC servos
- PLCs (programmable logic controllers)
- Manufacturing equipment
- Robots
- Commercial air conditioning
- Industrial lighting (e.g. luminaires)
Optimized for auxiliary power supply circuits in 400V AC industrial equipment
