Detection of earbud insertion in a case

A case comprising:

• a housing configured to enclose a first earbud and a second earbud;
• interface chips configured, via respective ports, to communicate data and transfer power to either of the first earbud or the second earbud;
• a power management unit (PMU) configured to provide a direct current (DC) voltage at a respective port of either of the first earbud or the second earbud;
• and
• a current-sensing circuit configured to detect a current,
• wherein the current is drawn by a capacitor of the first earbud or the second earbud upon insertion of the first earbud or the second earbud in the housing.

An earbud comprising:

• an interface circuit configured to mate with an interface circuit of a case upon insertion of the earbud in an enclosure provided by the case;
• a capacitor coupled to an input port of the interface circuit and configured to be charged by drawing a current from the interface circuit of the case upon the insertion of the earbud into the enclosure;
• and
• a current detection circuit configured to detect the current and send a signal to a processor of the earbud or the case indicating the insertion of the earbud into the enclosure.