Part Number:SM73201-ARC-EV
Hi,
End-customer found 6 units of the 160 units were fails in the PV field site during arc self testing. Two of the 6 units were sent back to DELTA Tainan. After analysis, ,Engineer found the problem on the Q1 transistor (Self Test Circuit in snoa564f application notes/white noise circuit). and after Q1 was changed to new one, the problem is gone.
Supplier of transistor: KEN
Q1: KTN222AS
1. How to choice the BJT of Q1 and Q2? How to choice BJT's beta value or related parameter for optimized considerations?
2. Could you describe the operating priciple of the Q1 and Q2 as red circle below?
Customer: WW class
Application: PVI for US market
