A Smart Gate Driver IC for GaN Power Transistors

Download or read book A Smart Gate Driver IC for GaN Power Transistors written by Jingshu Yu and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the growing demands for high frequency, high temperature, and high power density applications in power electronics industry, silicon is reaching its theoretical limits. Wide band gap materials, such as GaN and SiC, have become the most popular successor candidates to keep "More than Moore" alive, due to their superior properties and mature technological process. However, there are many design challenges for driving GaN power transistors, including tight restriction on the gate voltage, EMI and reliability issues due to the large dv/dt and di/dt slew rates, the precision timing control, etc. In this thesis, 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 um BCD GEN2 technology process for driving a d-mode GaN power HEMT in cascode configuration. The embedded CPU can configure all the digital control bits on-the-fly, with only 6 I/O pins. By using segmentation technique, this IC can suppress gate voltage spike and achieve switching node slope control. Compared with conventional fixed ROUT driving scheme, the gate voltage overshoot during transition is reduced by 89% with a load current of 5 A. In an 8 V to 15 V, 7.5 W boost converter operating at 1 MHz, an average EMI reduction of 4.43 dB is achieved between 40 MHz to 200 MHz, by utilizing dynamic driving strategy. When fSW = 2 MHz, the overall power conversion efficiency is improved by 6% at the rated output power. The programmable sense-FET and current sensing circuit can provide peak-current detection with a response time of 26 ns. This IC has many other add-on functions, including the active driving mode, which can change the best driving pattern on-the-fly. Compared to conventional gate drivers, the proposed driver IC offers a fully integrated solution, which eliminates the need for external controller, addition passive components, and analog circuit building for close loop regulation. System volume is reduced, while the design exibility is greatly improved.