Photo: Ahmed Morsi Ammar

New technology behind the world’s smallest power converter

Electrotechnology Electronics
Five young DTU researchers have developed a new technology for producing a power converter which is shaped like a small cube measuring only a couple of millimetres on each side.

The development of future mobile phones and laptops focuses on further decreasing the size while increasing the speed and adding new features.

Today, a mobile phone is not just a phone but an entire communication and entertainment centre complete with camera, GPS, web browser, sensors, gaming centre, and much more.

The energy source for mobile phones is either a USB cable plugged into a power grid or a battery. However, the electronic components for the different functions in the phones are powered by many different voltage domains.

A power supply system therefore ensures that the voltage is converted from USB or battery to the many voltage domains. Often, up to 15 different voltage domains are needed, each of which requires a power converter. The many power converters thus take up a lot of room.

Bottleneck for achieving smaller size removed
The interest in creating smaller power converters is thus great. The big challenge now is temperature. The small electrical circuits can easily heat up to 80°C, which is neither desirable when holding the phone in your hand, nor safe as it increases the risk of short circuits and fire.

“For our new technology, we’re using a new material as a base for the electrical circuits in the converter, and that’s silicon. Silicon prevents the formation of so-called hot spots with very high temperatures. The new converter will reach a maximum temperature of about 45°C, and that’s perfectly acceptable,” says Yasser Nour, DTU Electrical Engineering, who is one of the researchers behind the new converter.

“Silicon also has other advantages, because it can be found in large quantities in nature and is thus both sustainable and inexpensive to use,” he adds.

On top of the silicon, the researchers integrate the various active and passive components in the converter. This is done by stacking them up in three-dimensional layers, almost like a 3D printer.

Great interest from businesses
The market for the new converter is huge, not only in mobile phones, but also in, e.g., laptops, hearing aids, or wearables, which continuously read data from your body or from the surroundings.

“These electronic devices also need to be able to process ever increasing amounts of data quickly. They therefore require more power, while they still need to be as small as possible. This is where our new technology really comes into its own,” says researcher Ahmed Morsi Ammar, who also participated in the development of the converter.

Yasser Nour, Ahmed Morsi Ammar, Pere Llimós Muntal, Dennis Øland Larsen, and Hoá Lê Thanh are currently working on starting their own business based on the newly developed power converter. The first potential customers have already signed up and will soon receive a test transformer, so that they have the opportunity to test it themselves.