Power routing for dongles and adapters

A method of providing power to an accessory using a dongle, the method comprising, with the dongle:

• receiving power at a first receptacle and using the power received at the first receptacle to provide power to a first plug and a second receptacle, and to charge a charge storage circuit in the dongle;
• detecting that the power received at the first receptacle is no longer being received;
• then
• providing a signal to the first plug that power is not being received at the first receptacle;
• providing power to the second receptacle using the charge storage circuit;
• then, after a first duration;
• and
• receiving power at the first plug and using the power received at the first plug to provide power to the second receptacle.

An electronic system comprising:

• a host device having a receptacle;
• and
• a dongle having a plug to mate with the receptacle on the host device, the plug connected to a housing of the dongle, the housing having a first receptacle to connect to a charger and a second receptacle to connect to an accessory, the dongle further comprising:
• a first switch to couple a power supply received at the first receptacle to the second receptacle;
• detect circuitry to detect that the power supply received at the first receptacle is no longer being received and to send a signal to the host device indicating that the power supply received at the first receptacle is no longer being received;
• and
• a second switch to couple a charge storage circuit to provide a power supply to the second receptacle;
• wherein the host device further comprises:
• logic to receive the signal from the dongle indicating that the power supply received at the first receptacle of the dongle is no longer being received and to provide a power supply to the plug of the dongle within a first duration, and
• wherein the first switch of the dongle couples the power supply received from the host on the plug to the second receptacle.