Global Sources
EE Times-Asia
Stay in touch with EE Times Asia
EE Times-Asia > Power/Alternative Energy
Power/Alternative Energy??

ROHM's new DC/DC converter features minimum ON-Time

Posted: 22 Mar 2016 ?? ?Print Version ?Bookmark and Share

Keywords:power supply? dc/dc? converters? electronification?

Featuring a minimum ON time, ROHM develops BD51180TL, a step-down DC/DC converter that works for high-power applications like industrial equipment and automotive systems.

In recent years, there is a growing trend towards electronification to meet the need to conserve energy in all areas, including the automotive market where attention has focused on 48V hybrid vehicle systems that take safety into account and provide better fuel economy than conventional 12V systems. This is expected to increase the demand for DC/DC converters that can not only provide direct 3-5V output from 48V for driving control blocks and various functions, but are also capable of operating at high frequency (>2MHz) to prevent interference with AM radio bands and minimise the number of external components. To meet these market needs for high input, low output, and high switching frequency it is necessary to shorten the switching ON time.

Proprietary technology for controlling pulses in a very short time allowed ROHM to reduce the minimum ON time to an unprecedented 20ns C 6x shorter than conventional solutions C enabling stable step-down operation from 48V to 3.3V at a constant switching frequency of 2MHz. In addition, current mode control provides phase compensation required for constant voltage output with few external parts, contributing to miniaturisation while reducing customer design load. And integrating ROHM's high voltage MOSFET expands the input voltage range to 65V, 4.6x higher than conventional products, which is compatible with a wide range of applications. Additional features include multiple protection circuits and AEC-Q100 qualification that support the stringent demands in the automotive and industrial equipment sectors.

ROHM will be exhibiting this technology at APEC 2016, the premiere event in applied power electronics (for more information, click here).

Key Features

ROHM new tech

Figure 1: Breakthrough 20ns minimum ON-time control

Leveraging original technology for controlling pulses in a short period makes it possible to reduce the minimum ON time to an unprecedented 20ns, 6x shorter than the conventional level. This ensures stable 3.3V output from 48V battery systems for driving various functions and control blocks while enabling 2MHz operation that prevents interference with AM radio band frequencies.

current mode control

Figure 2: Easy phase compensation with current mode control

Switching power supplies such as DC/DC converters typically include a feedback control circuit along with phase compensation to prevent abnormal oscillation. ROHM's new IC employs current mode control capable of controlling the current in very short pulse widths, simplifying phase compensation and reducing customer design load. Two components are required to achieve stable operation over a wide input voltage range.

Expanded input voltage range

Figure 3: Expanded input voltage range

Integrating ROHM's high voltage MOSFET makes it possible to expand the input voltage range by over 4.6x compared with conventional products, from 12V to 65V, enabling suitability for a range of applicationsCincluding high-voltage automotive systems and industrial equipment.

Compact high-heat dissipation package

Generally, increasing the breakdown voltage requires greater heat dissipation, making it difficult to decrease size. In contrast, the VQFN24SV4040 adopts a backside heat sink that reduces size to a compact 4.0x4.0x1.0mm, 54% smaller than conventional products.

Multiple protection circuits

Standard protection circuits are built in to ensure safe operation and provide a greater degree of reliability.

AEC-Q100 Qualified

Over Current Protection

Input Under Voltage Lockout Protection

Input Over Voltage Protection

Output Overvoltage Protection

Thermal Shutdown

Short-Circuit Protection

Article Comments - ROHM's new DC/DC converter features ...
*? You can enter [0] more charecters.
*Verify code:


Visit Asia Webinars to learn about the latest in technology and get practical design tips.

Back to Top