Diamond Electric in Japan has designed a 1kW isolated bidirectional DC-DC converter (IBDC) inverter using gallium nitride (GaN) devices that is the size of a credit card. by Nick Flaherty @ eenewseurope.com:
The technology can substantially reduce the weight and size of DC-DC converters for rechargeable batteries in electric vehicles (EVs) and smart grids as well as uninterruptible power supplies (UPS).
The IBDC combines both charger and discharger circuits with a patented control architecture with switching up to 2MHz and a current range of -3.7 to +3.7A for the 270V to 330V input and output. This has enabled smaller magnetics for a footprint of 93.5 mm x 60 mm x 10.5 mm, excluding the control circuit and heatsink, a quarter the size of the existing designs.
As well as enabling the higher frequency, the use of GaN power devices allows a conversion efficiency of 95%.
1kW bidirectional DC-DC converter with credit card footprint – [Link]