Figure 4-4 TIDM-1000 3-Phase Vienna PFC Rectifier

In 800V DC architectures, 3-phase Vienna PFC topology is widely adopted in the PFC stage (see Figure 4-4) because this topology reduces the voltage stress on power devices to half of the DC link voltage, enabling the use of mature 650V MOSFETs and delivering lower switching losses compared to two-level converters [see references 7 and 12].

Figure 4-5 One BDG Equals Four Back-to-Back Si MOSFET

In Vienna PFC circuits, the power switches are used in serial with a back-to-back configuration, to handle the AC in two directions. But, the bidirectional GaN (BDG) is a true, normally-off, monolithic, bidirectional switch, which can directly handle the current in two directions, so the BDG can be equal to four Si or SiC MOSFETs with the same on-resistance, as Figure 4-5 presents. This innovation holds significant promise, but requires further market validation. The TIDA-01606 reference design demonstrates the application of the BDG in T-type converters and provides preliminary data supporting the potential of this application [see reference 3].