Method and apparatus for improving power characteristics in a system having a reduced power mode

A system comprising:

• a first device having an active mode and a low power mode;
• an auxiliary circuit coupled to the first device and receiving a power budget from the first device;
• a signal source coupled to the first device to provide a signal that switches when the first device is in the active mode and does not switch when the first device is in the low power mode;
• an activity monitor coupled to the signal source to detect switching;
• and
• control logic decoupling power to the auxiliary device in an absence of switching.

A method comprising:

• monitoring a signal source that switches when a device is in an active mode and does not switch when the device is in a low power mode;
• driving a switch to disconnect power to an auxiliary circuit if the monitoring reflects the low power mode has been entered;
• and
• restoring power to the auxiliary circuit faster than the device can transition from the low power mode to the active mode when a transition from the low power mode to the active mode occurs.