News: Microelectronics
18 December 2020
EPC’s eGaN FETs used in BrightLoop’s DC-DC buck converters
Efficient Power Conversion Corp (EPC) of El Segundo, CA, USA – which makes enhancement-mode gallium nitride on silicon (eGaN) power field-effect transistors (FETs) and integrated circuits for power management applications – says that its EPC2029 enhancement-mode gallium nitride (eGaN) FET transistors have been used by BrightLoop Converters of Paris, France (which develops and manufactures high-efficiency, high-reliability power converters) to greatly reduce the size, cost and improve the reliability of its latest BB SP DC-DC buck converters.
By switching from silicon transistors to gallium nitride, BrightLoop was able to increase the switching frequency of its design from 200kHz to 600kHz, while keeping the same efficiency. This design change increased power density by a factor of about two, resulting in lower cost by enabling the implementation of a smaller enclosure.
The EPC2029 is an 80V, 48A eGaN FET featuring a 1mm ball pitch. The wider pitch allows for the placement of additional and larger vias under the device to enable high current-carrying capability despite the extremely small 2.6mm x 4.6mm footprint.
Compared with a state-of-the-art silicon power MOSFET with similar on-resistance, the EPC2029 is much smaller and has many times superior switching performance, claims EPC, making it suitable for applications such as BrightLoop’s high-frequency BB SP DC-DC converter.
BrightLoop’s converters are used primarily in motorsports and supercars, with other applications including commercial and off-highway vehicles. Future higher-power versions are coming next year to address the mild hybrid applications such as electrical starting assistance.
The BB SP is relevant in any dual-voltage architecture (14V/48V or 14V/24V), or where a certain load is available only with a voltage that is different from the regular network (for example, a 48V pump on a 14V car), in which case the conversion can be done by the BB SP locally, just in front of the load.
To make the use of BB SP interesting, it needs to have negligible losses and weight compared with the rest of the system. This is possible due to EPC’s eGaN FETs. For example, a 48V actuator plus BB SP using GaN can be lighter than the equivalent 12V actuator.
Due to BrightLoop’s expertise in ultra-high-speed digital control, another important feature is the ability to implement a closed-control loop at 600kHz (the same as the switching frequency). The resulting bandwidth is so high that very little capacitance is required. So, electrolytic capacitors can be avoided, and only ceramic capacitors were used in the BB SP, further reducing the size and cost while dramatically improving reliability.
“Using EPC products has allowed us to design best-in-class solutions for automotive applications with converters that are drastically smaller and lighter than competition, such as the BB SP,” comments BrightLoop’s CEO Florent Liffran.
“This is a great example of where our eGaN FETs demonstrate real advantage over silicon FETs by delivering performance in a significantly smaller package and the extreme reliability that is needed in these ultra-fast supercars,” says Wolfram Krueger, EPC’s VP of sales for EMEA.
EPC E-mode GaN FETs Power electronics
