Categorized | Industry News, ROHM


Posted on 05 September 2019

ROHM Offers a Lineup of 24 Power Supply ICs for AC/DC Converters




Integrated power MOSFET results in the industry’s highest efficiency and smallest form factor




Willich-Munchheide, August 28th, 2013 - ROHM Semiconductor has recently announced the development of power supply ICs for AC/DC converters in primary power supplies for home appliances and AC adapters. The BM2xxx/F series consists of 24 models that utilize a proprietary low ON resistance SJ MOSFET and feature circuit optimization, resulting in industry-leading efficiency and low noise. In addition, a surface mount type is available in the SOP8 package that contributes to set miniaturization. ROHM is working on expanding its lineup to achieve high efficiency in a wide range of home electronics, including appliances, TVs, and monitors.

AC/DC converters, used to configure the primary power supply in electronic devices, must meet market needs for improved energy and space savings along with greater convenience. Generally, there is a strong demand for power supply ICs in AC/DC converters to be Energy Star compliant and provide high efficiency operation that includes standby power. Also, the increased number of components leads to a larger mounting area, presenting additional challenges regarding design complexity and time.

In response, ROHM utilized power supply technology cultivated from developing LDOs, DC/DC converters, and the like along with discrete transistor analog power technology to develop the BM2Pxxx/F series, optimized for AC adapters, home electronics, and office equipment up to 25W that require high efficiency operation in a compact form factor.

ROHM AC-DC converter data


Samples are already available, OEM quantities as of September 2013

Key Features:

1.High efficiency operation contributes to greater energy savings

Converter efficiency comparisonIn order to improve efficiency a proprietary high performance super junction MOSFET is utilized, while exhaustive optimization of the driver circuitry enabled the company to maximize MOSFET performance. As a result, ROHM products cleared the 86.35% efficiency rating required by Energy Star 6.0. In fact, an efficiency more than 87% is possible by simply replacing conventional products with ROHM ICs (100VAC, 25W applications), while greater than 90% can be achieved through optimization of peripheral components.

2.Improved efficiency also reduces standby power

Reduced standby powerThe internal super junction MOSFET features a voltage resistance of 650V, low ON resistance (just 4.0Ω even with the SOP8 package), low gate charge Qg, and high-speed switching capability. In addition, standby power consumption is less than 20mW (@100VAC) for a 25W adapter and only 30mW @ 230VAC – significantly less than the 100mW required by the Version 6.0 Energy Star. And even lower consumption is possible by adjusting the peripheral circuitry.

3.Compact package

47 percent mounting area reductionAC/DC systems typically use a planar-type MOSFET, which is difficult to miniaturize due to problems associated with heat dissipation. In contrast, ROHM uses a super junction MOSFET and integrate a number of protection functions, enabling the company to offer a variety of package types in the 8W and under class, from conventional DIP7 to surface mount SOP8 (6.2x5.0x1.5mm) that reduces mounting area by 47% for easier design and board layout.


  • Super Junction MOSFET
    A type of power MOSFET that utilizes a three-dimensional depletion spread for lower switching loss than conventional products.
  • PWM (Pulse Width Modulation)
    A modulation method that lengthens and shortens the output time of the pulse signal to control current or voltage.
  • Energy Star
    An international standard for energy efficiency in consumer products established in 1992 in the US by the EPA and the Department of Energy. Target products include PCs, printers, and multifunction devices. It was later adopted in Japan in 1995 by the Ministry of Economy, Trade, and Industry, which implemented an ‘International Energy Star Program.’ Version 6.0 is currently under revision.

About ROHM Semiconductor

ROHM Semiconductor is a global company of 304,6 billion yen (3,8 Billion $) revenue with 21,295 employees in the last fiscal year ending March 2012. ROHM Semiconductor develops and manufactures a very large product range from the Ultra Low Power Microcontroller, Power Management, Standard ICs , SiC Diodes, Mosfets and Modules , Power Transistors and Diodes, LEDs to passives components such as Resistors, Tantalum Capacitors and LED display units, thermal Printheads in state-of-the-art manufacturing plants in Japan, Korea, Malaysia, Thailand, the Philippines, China and Europe.  

Lapis Semiconductor (former OKI Semiconductor), SiCrystal AG and Kionix are companies of ROHM Group.

ROHM Semiconductor Europe has its head office near Dusseldorf serving the EMEA region (Europe, Middle East and Africa). For further information please contact

Contact Information:

ROHM Semiconductor GmbH
Media Department
Karl-Arnold-Str. 15
D-47877 Willich-Münchheide
Phone: +49 2154 921 0
Fax: +49 2154 921450

KEK Concept GmbH
Evelyn Stepken
Hofer Str. 1
D-81737 Munich
Phone: +49 89 673 461-30
Fax: +49 89 673 461-55







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