Imec demonstrated that high-end integrated power systems can be realized on a single die. At the PCIM 2019 conference, this week in Nüremberg, the Leuven research institute showed off a GaN-on-SOI half-bridge monolithically integrated with drivers. Mounted on a buck converter test board, the chip converts an input voltage of 48 V to an output voltage of 1 V, with a pulse width modulation signal of 1 MHz.
Half-bridges are currently assembled from discrete components packaged either separately or together. Integration on a single chip would save costs, but using a GaN substrate is expensive and impractical and integration on GaN-on-Si is challenging because of a back-gating effect that negatively affects performance. Hence Imec’s choice for GaN-on-SOI or proprietary GaN-on-QST technology, which eliminate back-gating and reduces switching noise that disturbs control circuits.
“Someone might think that using SOI or QST wafers instead of silicon wafers will result in more expensive technology. However, with GaN-on-Si several discrete devices need to be individually packaged, sometimes with advanced packages to take advantage of the GaN fast switching performance. Instead, with Imec’s GaN IC technology, the full converter including drivers and analog blocks is on-chip, which can then be packaged with simple packaging technology. This dramatically saves on the cost of the final power system,” explains Denis Marcon, a business development manager at Imec.
Imec aims to boost performance and extend its power electronics platform with additional co-integrated components, such as Schottky diodes and depletion-mode HEMTs.