In the schematic of TIDA-01505:
1、Why use Q8(DXT2222A-13) for the UCC28C43QDRQ1? AND does it necessary to use SOT-89 package?
2、When we design a new application. How should we design the peripheral parameters of U4(TL431AQDBZRQ1), such as R70 & C68 & C71 in the image below: