A power supply includes an LLC resonant power converter to provide a first reference signal having a first voltage. The power supply also includes a DC-DC power converter to provide a second reference signal having a second voltage. The DC-DC converter receives power from the first reference signal. The power supply further includes a switch circuit including a first input to receive the first reference signal, a second input to receive the second reference signal, an input to receive a switch control message, and an output coupled to a power rail. The switch circuit is configured to connect the first reference signal and the second reference signal to the power rail based on the switch control message.