Hi, Andy:
Thank you for the opinion. Yes, it's horizontal. (It's late, and I felt sleepy.)
I have fixed the TL431/TI with LT1431 (LTspice built-in lib). The file is at here:
I had been aware of the Ix current (constant current source to feed FB) would affect the Vsc ripple, but it's not mentioned the absolute value.
I guess that's secret parameters of the vendor.
I don't have the ability to reveal any secrets of the vendor, it's just for fun and some simple circuit topology test.
Any opinion is appreciated.
