ROHM unveil 24 power supply ICs for AC-DC converters

In addition, 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 utilised 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.

Key features:

1．High efficiency operation contributes to greater energy savings

In 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

The 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

AC-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.

Availability:

Samples are already available, OEM quantities as of September 2013.