Overshoot Prevention in Monolithic GaN by Ultra-Low ESL Gate Loop Design Using Chip-Scale Capacitors and Gate Driver Pull-Up Path Tuning Technique

Despite monolithic integration of GaN gate drivers with the power stage, some parasitic gate loop inductance remains, including connections to off-chip decoupling capacitors. On-chip capacitors, however, complicate the gate loop design by adding another pole to the system. An LC-RC resonant tank replaces the conventional RLC model, which is insufficient. Ultra-low ESL decoupling using chip-scale silicon capacitors bonded directly to the GaN-IC is identified as most effective by measurements for PCB and bonded MLCC and SiCap gate loop decoupling. A voltage-tuning technique-based gate driver, implemented on a GaN-IC, is applied to adapt to the remaining loop inductance and reduce critical overshoot while ensuring fast switching.