To see how an FPA solution would compare to an intermediate-voltage bus design, consider an application that requires three voltage outputs with a total load of 200 W. A minimum implementation with the intermediate voltage bus would likely consist of a quarter-brick sized bus converter plus five or six POL converters. Multiple POLs are necessary due to the limited-current output capabilities of the POLs (generally 20 A or less).
In contrast, an FPA-based design might consist of a single PRM plus three VTMs, assuming that only a single output requires very tight load regulation. The FPA approach allows a smaller, more efficient on-board implementation with competitive or better pricing than the intermediate-voltage bus method. Even if multiple PRMs are needed for independently regulated outputs, the FPA approach still enables a more compact solution