A power stage controller (106 A) includes: a multi-phase pulse control circuit (124); a current sense circuit (204); a comparator (116); an error amplifier (108); and a mode controller (135). The mode controller (135) includes a mode controller input (136) and a summation circuit (210). The summation circuit (210) has a first summation circuit input (214), a second summation circuit input (212) and a summation circuit output (216), the first summation circuit input (214) is coupled to the error amplifier output (114), and the summation circuit output (216) is coupled to the first comparator input (118). The mode controller (135) is configured to: select one of a main controller mode or a secondary controller mode responsive to a mode control voltage at the mode controller input (136); bypass the summation circuit (210) responsive to selection of the main controller mode; and enable the summation circuit (210) responsive to selection of the secondary controller mode.