A power supply system includes at least a first power supply module and at least one redundant power supply module. The at least one power supply module supplies power to an output terminal. The at least one redundant power supply module operates in a first state and in a second state. In the first state the second power supply module supplies power to the output terminal. In the second state the second power supply module provides standby power and operates in a burst mode (for example, such as a discontinuous conduction mode).