Two approaches are examined for the design a pulse width modulated (PWM) feedback control scheme regulating a full bridge buck converter in both stabilization and AC signal tracking tasks. The first approach is based on a direct strategy for the specification of a static PWM feedback control which accomplishes asymptotic stabilization to a preselected constant operating point for the output capacitor voltage. The same approach is also examined for the asymptotic output tracking of AC reference signals. The second approach, or indirect approach, proposes a dynamical feedback regulation scheme based on input inductor current stabilization or tracking using reference signals obtained via partial inversion of the system dynamics. The indirect approach emphasizes the use of Fliess' generalized observability canonical form of the average converter model.