One example discloses an apparatus for power management, including: a circuit having a first power-domain and a second power-domain; wherein the first and second power-domains include a set of operating parameter values; a circuit controller configured to incrementally sweep at least one of the operating parameter values of the first power-domain; a circuit profiler configured to derive a total power consumption profile of the circuit based on the circuit's response to the swept operating parameter value; wherein the circuit controller sets the operating parameter values for the first and second power-domains based on the total power consumption profile of the circuit.