A 200V Monolithic GaN Half-Bridge with Active Gate Driver Including a Fast dv/dt Feedback Loop

Gallium Nitride (GaN) transistors high switching speed enables lower switching losses compared to silicon transistors. However, their high switching speed can also cause electromagnetic disturbances (EMI), thus requiring new methods to mitigate the tradeoff between switching losses and EMI. This work presents a monolithic GaN Half-Bridge power stage using an on-chip Active Gate Driver (AGD) including a very fast dv/dt feedback loop to control the turn-on speed of the power transistor on a GaN-on-SOI technology. This feedback loop control method can achieve a 45% reduction of the dv/dt with a smaller impact on the commutation energy E<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</inf> than a classical method using only either the gate resistor or the gate width of the driving transistor as a control parameter. Finally, a 2.5 × 5mm² prototype is developed using the IMEC GaN-on-SOI technology.