Power communication apparatus using microphone jack

A host communication module, which is provided in a host device that can be connected to a slave device, comprising:

• a terminal connection unit receiving a bias voltage from the host device and connected to at least one terminal for electrical connection to the slave device;
• and
• an attribute recognition unit detecting a drop in the bias voltage, determining the slave device as being an active slave device if the dropped bias voltage is higher than a key recognition voltage and lower than a regular bias voltage, and determining the slave device as being a passive slave device if the dropped bias voltage is not lower than the regular bias voltage, and
• a host current fluctuation generator generating a power pulse for the active slave device by encoding a power voltage into a first voltage or a second voltage different from the first voltage, and supplying the power pulse to the active slave device via a microphone jack, and the host current fluctuation generator generating a polling signal and transmitting the polling signal to the active slave device using the power pulse if the host device needs to be switched from a reception mode to a transmission mode,
• wherein the polling signal lowers the voltage of the power pulse to a third voltage.

A host communication module provided in a host device, which can be connected to a slave device, comprising:

• a terminal connection unit receiving a bias voltage from the host device and connected to at least one terminal for electrical connection to the slave device;
• and
• an attribute recognition unit detecting a variation in a frequency of the bias voltage, determining the slave device as being an active slave device if the varied frequency of the bias voltage is higher than a predetermined frequency band, and determining the slave device as being a passive slave device if the varied frequency of the bias voltage is not higher than the predetermined frequency band, and
• a host current fluctuation generator generating a power pulse for the active slave device by encoding a power voltage into a first voltage or a second voltage different from the first voltage, and supplying the power pulse to the active slave device via a microphone jack, and the host current fluctuation generator generating a polling signal and transmitting the polling signal to the active slave device using the power pulse if the host device needs to be switched from a reception mode to a transmission mode,
• wherein the polling signal lowers the voltage of the power pulse to a third voltage.