Monolithic Integrated p-GaN HEMT with Lateral Rectifier to Reduce the Dead Time Loss

p-GaN HEMTs are favored for bridge topology applications where they act as the freewheeling transistors to commute the current at the dead time. To address the false turn-on by crosstalk, a negative turn-off voltage is commonly used. Unlike Si or SiC MOSFESTs, the negative turn-off voltage will increase the voltage drop of VDS and the dead time loss. To reduce the dead time loss, a monolithic integrated p-GaN HEMT, coupled with a lateral rectifier (LR), is fabricated. The electrical test shows there is no degradation when it works in the forward operation. Additionally, a synchronous buck converter was constructed to test the effectiveness of this approach in a circuit-level application. Experimental data demonstrate a 31 % reduction of the dead time loss and a significant decrease in current oscillation at the dead time.