Linear Assisted DC/DC Converter for Pulsed Mode Power Applications

This paper presents a linear assisted DC/DC converter to increase the response speed and power density of pulsed mode applications, including radar systems. The proposed architecture includes two power paths: (1) a full bridge converter as high power path for voltage control to efficiently process the main power and (2) a linear amplifier as low power path to achieve fast response speed by compensating current difference between high power path and pulsed mode load. Hence, though the high power path responds slowly, output voltage variations during pulsed transients can be reduced. GS66516B, 650V Gallium Nitride enhancement mode high electron mobility transistors (GaN E-HEMT) are used as switching devices to enable higher operating frequency with less loss. Finally, a 400V to 2SV, 900W converter is designed for a 4 A (average) / 32A (peak) pulsed load scenario. Simulation results and design analysis are described, proving the concept.