A smart gate driver IC for GaN power transistors

In this paper, an integrated smart gate driver IC with segmented output stage topology, programmable sense-FET, current sensing circuits and an on-chip stacked-based CPU for flexible digital control is presented. This IC is fabricated using TSMC's 0.18 μm BCD GEN2 process for driving a d-mode GaN power HEMT in cascode configuration. Using a segmentation technique, this IC can dynamically adjust the gate driving strength during switching transition to achieve slope control and EMI reduction. Programmable sense-FET and current sensing circuit monitor the load current for peak-current regulation. The embedded CPU can update all digital configuration bits on-the-fly. In dynamic driving mode, current spike at turn-on transition is reduced by 83% without sacrificing the switching speed. Current sensing circuit can detect peak current value and response within 5 ns. The pre-stored driving patterns can be loaded to the driving circuit in 1 μs under active driving mode.