SLUAAJ7 June 2022 UCC256402 , UCC256403 , UCC256404
Figure 2-15 shows the FB pin voltage during no load. Here we can see that FB pin voltage is close to 5.6 V whenever FB pin current value is smaller than the sum of IFB current source and the clamp current source. Otherwise it is at zero.
Figure 2-15 Ch1- LO, Ch2-FB, Ch3- (HO-HS),
Ch4-Iout