Although discrete GaN HEMT power devices have many advantages as explained earlier in this presentation, they also have some drawbacks that make the standalone operation more challenging. Lower V_th which has a risk of self-turn-on, and lower gate voltage maximum rating which lowers device reliability. When discrete GaN HEMTs are driven by external gate drivers, special attention is needed to the PCB layout to reduce parasitic inductance due to the very high-speed operation. When parasitic inductance is present, a large voltage spike will occur during fast gate drive transients. The lower V_th and lower maximum gate voltage rating will be susceptible to potential problems. To overcome these challenges, both GaN HEMT devices and specific gate drivers designed to drive GaN HEMT are combined into one package (often called a power stage). When both are placed into one package, it reduces the overall parasitic inductance to avoid the pitfalls mentioned before. In addition, the combination of the gate driver and GaN HEMT allows compatibility of operating with general gate drivers and controller chips.