SLUAAJ7 June 2022 UCC256402 , UCC256403 , UCC256404
As UCC25640x is a primary side LLC controller, the output voltage/current is regulated by a voltage/current regulator circuit located on the secondary side of the isolation barrier. The demand signal from the secondary side regulator circuit is transferred across the isolation barrier via an opto-coupler (U1) as shown in Figure 2-11.