SLUA669B March 2013 – September 2023 UCC27511 , UCC27531 , UCC27532 , UCC27533 , UCC27536 , UCC27537 , UCC27538
Signal Isolation
The input signals of U1 are isolated in Figure 2-5, with the isolated gate driver, UCC53xx. The isolated bias, a transformer, allows the gate signal to Q1 to have a floating reference that can move as the switch-node moves in voltage.
High-Side Bias
In Figure 2-5, signal isolation is not needed because the gate drivers provide this internally. In this configuration, a bootstrap supply is not needed because of the isolated bias. Vbias1, referenced to power ground, supplies the floating bias for the high-side.