D11.8 - GaN-Based Two Stage Point-of-Load (PoL) Converter with 2.5D Embedded Substrate Implementation

High-density, high-step-down, high-current point-of-load (PoL) converter plays an important role in future computing and AI research. This paper presents a 48-1V POL target achieving up to 92\% with a heterogeneous integration for AL/ML computing chips targeting a 100A full load operation. This PoL converter will realize a two-stage cascade converter with the first stage being a hybrid switch capacitor converter at 200 kHz. The 2nd stage will be an interleaved 4-phase buck converter, tested at 1 MHz. The PoL package will implement a 2.5D implementation using embedded passive and actives to create an active substrate design by using a electro-thermal co-design methodology with a goal to create a low parasitic inductance vertical power loop. A embedded prototype will be creating using standard PCB manufacturing methods to create the smallest possible area. Different PCB substrates such as insulated metal core (IMS) PCBs will be explored to combine both the electrical and thermal design into a single package. Finally, a 3D implementation will be explored will explore to improve modularity and to reach higher current demands.