Taking GaN-based power from AC to processor
Achieving three times the power density compared to existing solutions, TI is this week demonstrating four separate reference designs based on its LMG5200 80V, 10A integrated GaN FET power stage and LMG3410 high-voltage GaN power stage solutions.
The GaN-based solutions fundamentally change both the architecture and density of the entire power system from the AC to the processors.
By enabling a totem-pole topology, GaN devices such as the LMG3410 reduce the number of active power switches and filter inductors by 50%. A four- to tenfold increase in switching frequency (continuous conduction mode [CCM] or critical conduction mode [CRM] operation) significantly reduces the size of magnetics while improving overall efficiency to over 99%, versus 96% for today’s titanium-grade power supplies. Interleaved solutions further enable designers to scale the power stage to meet system demand.
The DC-DC stage takes advantage of GaN’s switching characteristics to push the resonant converter to over 1MHz. The high frequency reduces the magnetics while improving power density and efficiency. The smaller form factor further enables the emerging high-voltage distribution systems in data centres for 380V-to-48V converters.
GaN also has a major impact on the point of load DC-DC converters. First, it enables a single step conversion from 48V in order to power processors, memories and other loads directly, reducing component counts on precious printed circuit board (PCB) real estate by as much as 50% while reducing footprints by 75%. Second, the half-bridge current double topologies using the LMG5200 enable designers to easily stack the power stages for different load demands and placed closely to the load for best transient performance.